Graphitic Carbon Nitride: a Highly Electroactive Nanomaterial for Environmental and Clinical Sensing

Total Page:16

File Type:pdf, Size:1020Kb

Graphitic Carbon Nitride: a Highly Electroactive Nanomaterial for Environmental and Clinical Sensing sensors Review Graphitic Carbon Nitride: A Highly Electroactive Nanomaterial for Environmental and Clinical Sensing Azeez O. Idris * , Ekemena O. Oseghe, Titus A. M. Msagati , Alex T. Kuvarega, Usisipho Feleni and Bhekie Mamba Institute for Nanotechnology and Water Sustainability (iNanoWS), Florida Campus, College of Science, Engineering and Technology, University of South Africa, Johannesburg 1709, South Africa; [email protected] (E.O.O.); [email protected] (T.A.M.M.); [email protected] (A.T.K.); [email protected] (U.F.); [email protected] (B.M.) * Correspondence: [email protected] Received: 12 August 2020; Accepted: 23 September 2020; Published: 10 October 2020 Abstract: Graphitic carbon nitride (g-C3N4) is a two-dimensional conjugated polymer that has attracted the interest of researchers and industrial communities owing to its outstanding analytical merits such as low-cost synthesis, high stability, unique electronic properties, catalytic ability, high quantum yield, nontoxicity, metal-free, low bandgap energy, and electron-rich properties. Notably, graphitic carbon nitride (g-C3N4) is the most stable allotrope of carbon nitrides. It has been explored in various analytical fields due to its excellent biocompatibility properties, including ease of surface functionalization and hydrogen-bonding. Graphitic carbon nitride (g-C3N4) acts as a nanomediator and serves as an immobilization layer to detect various biomolecules. Numerous reports have been presented in the literature on applying graphitic carbon nitride (g-C3N4) for the construction of electrochemical sensors and biosensors. Different electrochemical techniques such as cyclic voltammetry, electrochemiluminescence, electrochemical impedance spectroscopy, square wave anodic stripping voltammetry, and amperometry techniques have been extensively used for the detection of biologic molecules and heavy metals, with high sensitivity and good selectivity. For this reason, the leading drive of this review is to stress the importance of employing graphitic carbon nitride (g-C3N4) for the fabrication of electrochemical sensors and biosensors. Keywords: graphitic carbon nitride (g-C3N4); heavy metals; biosensors; electrochemical sensors; nanoparticles 1. Introduction Graphitic carbon nitride (g-C3N4) is a two-dimensional conjugated polymer consisting of carbon and nitrogen. It is obtained from different carbon materials analogues by replacing carbon atoms with nitrogen atoms [1]. Also, graphitic carbon nitride (g-C3N4) is one of the oldest documented polymers in the literature with the general formula (C3N3H)n; the history of this material can be dated as far back as 1834 [2]. According to the literature, the carbon nitride (CN) material was first studied in 1834 when Berzelius obtained a linear CN polymer and named it “melon” [2]. This breakthrough led to the discovery of graphitic carbon nitride (g-C3N4), prepared by thermal decomposition of mercuric thiocyanate by Franklin in 1922 [3]. In 1989, numerous studies indicated that if carbon could replace silicon in the structure of silicon nitride (β-Si3N4), a very hard carbon nitride (β-C3N4) may be obtained [3]. Furthermore, in 1966, Teter and Hemley predicted various phases of several allotropic forms of carbon nitride, which include α-C3N4, β-C3N4, cubic-C3N4, pseudo-C3N4, and graphitic-C3N4 [3]. It was reported that all the phases of the CN materials are super-hard except g-C3N4, and it was Sensors 2020, 20, 5743; doi:10.3390/s20205743 www.mdpi.com/journal/sensors SensorsSensors 20202020, 20, ,20 x, FOR 5743 PEER REVIEW 2 of2 of29 28 to be the most stable allotrope under ambient conditions [3]. This report revealed the ease of modifyingdocumented the structure to be the mostand the stable morphology allotrope under of graphi ambienttic carbon conditions nitride. [3 ].As This a result, report the revealed chemistry the easeof differentof modifying morphologies, the structure structures, and the and morphology graphitic ofcarbon graphitic nitride carbon (g-C3N4) nitride. applications As a result, has the attracted chemistry considerableof different morphologies,interest from structures,scientists and and industrial graphitic carboncommunities nitride (g-Cin employing3N4) applications this material has attracted for variousconsiderable analytical interest applications. from scientists and industrial communities in employing this material for various analytical applications. The carbon and hydrogen atoms in graphitic carbon nitride (g-C3N4) are bonded together by sp2 The carbon and hydrogen atoms in graphitic carbon nitride (g-C N ) are bonded together by hybridization. In graphitic carbon nitride (g-C3N4), both carbon and3 nitrogen4 atoms are sp2 2 2 hybridizedsp hybridization. and are connected In graphitic by σ carbon bonds nitrideforming (g-C a hexagonal3N4), both struct carbonure. and This nitrogen structure atoms is called are spa σ triazinehybridized ring, and each are connected of these rings by isbonds linked forming to a small a hexagonal unit connected structure. by a This C–N structure bond. There is called is a a triazine ring, and each of these rings is linked to a small unit connected by a C–N bond. There is a consensus that graphitic carbon may have two chemical structures, namely g-C3N4 with a triazine consensus that graphitic carbon may have two chemical structures, namely g-C N with a triazine ring ring (C3 N3), which belongs to the R3 m space group, and the other structure3 consists4 of the tri-s- (C N ), which belongs to the R3 m space group, and the other structure consists of the tri-s-triazine triazine3 3ring (C6N7) [4]. In graphitic carbon nitride (g-C3N4,) each triazine ring is connected by the nitrogenring (C 6atomN7)[ at4]. the In end, graphitic forming carbon a noti nitrideceably (g-C expanded3N4,) each planar triazine grid ringstructure. is connected by the nitrogen atomGraphitic at the end, carbon forming nitride a noticeably (g-C3N4) expanded has recently planar fascinated grid structure. researchers' interest due to its outstandingGraphitic properties, carbon nitrideincluding (g-C low-cost,3N4) has recently large surf fascinatedace area, researchers’ earth-abundant, interest fast due electron to its outstanding transfer π π π-properties,π conjugation including structure, low-cost, metal-free, large surface excellent area, earth-abundant, visible-light-driven fast electron polymeric transfer semiconductor,- conjugation biocompatibility,structure, metal-free, and catalytic excellent properties visible-light-driven [5,6]. Figure 1 depicts polymeric graphitic semiconductor, carbon nitride's biocompatibility, key features and catalytic properties [5,6]. Figure1 depicts graphitic carbon nitride’s key features that spurred that spurred scientists towards employing graphitic carbon nitride (g-C3N4) for various analytical fields.scientists towards employing graphitic carbon nitride (g-C3N4) for various analytical fields. It Itis is important important toto emphasizeemphasize that that the the excellent excellen catalytict catalytic and biocompatibilityand biocompati propertiesbility properties of graphitic of carbon nitride (g-C N ) have inspired various scientists to utilize this material to construct multiple graphitic carbon nitride3 4(g-C3N4) have inspired various scientists to utilize this material to construct multiplesensors sensors and bio-(sensors). and bio-(sensors). Thus, Thus, this reviewthis review aims aims to provide to provide a comprehensive a comprehensive assessment assessment of of the synthesis and application of graphitic carbon nitride (g-C N ) to construct sensors and biosensors. the synthesis and application of graphitic carbon nitride (g-C3 3N44) to construct sensors and biosensors. FigureFigure 1. Critical 1. Critical properties properties of graphitic of graphitic carbon carbon nitride nitride (g-C3N (g-C4) that3N promote4) that promote its application its application for sensor for fabrication.sensor fabrication. 2. Preparation of Graphitic Carbon Nitride (g-C3N4) 2. Preparation of Graphitic Carbon Nitride (g-C3N4) Several synthesis routes have been reportedly used to prepare graphitic carbon nitride (g-C3N4), Several synthesis routes have been reportedly used to prepare graphitic carbon nitride (g-C3N4), taking cognizance of the relationship between the structure of the material and morphologic features. taking cognizance of the relationship between the structure of the material and morphologic features. In summary, top-down and bottom-up approaches are the synthesis routes that are generally employed In summary, top-down and bottom-up approaches are the synthesis routes that are generally to synthesize various morphologies of graphitic carbon nitride (g-C3N4)[6]. The former involves liquid employed to synthesize various morphologies of graphitic carbon nitride (g-C3N4) [6]. The former and thermal exfoliation methods, while the latter involves a solvothermal approach, supramolecular involves liquid and thermal exfoliation methods, while the latter involves a solvothermal approach, aggregation, and soft and hard templates [6]. The top-down synthesis route involves the sequential supramolecular aggregation, and soft and hard templates [6]. The top-down synthesis route involves the sequential breaking down of larger blocks of graphitic carbon nitride (g-C3N4) into smaller units, Sensors 2020, 20, 5743 3 of 28 breaking down of larger blocks of graphitic carbon nitride (g-C3N4) into smaller units, g-C3N4 nanosheets multilayer, and single-layer structures. Similarly,
Recommended publications
  • Graphitic Carbon Nitride-Based Composite in Advanced Oxidation Processes for Aqueous Organic Pollutants Removal: a Review
    processes Review Graphitic Carbon Nitride-Based Composite in Advanced Oxidation Processes for Aqueous Organic Pollutants Removal: A Review Yu Shen, Antonio J. Dos santos-Garcia and María José Martín de Vidales * Department of Mechanical, Chemical and Industrial Design Engineering, ETSIDI, Universidad Politécnica de Madrid (UPM), 28012 Madrid, Spain; [email protected] (Y.S.); [email protected] (A.J.D.s.-G.) * Correspondence: [email protected]; Tel.: +34-91-067-7722 Abstract: In recent decades, a growing number of organic pollutants released have raised world- wide concern. Graphitic carbon nitride (g-C3N4) has drawn increasing attention in environmental pollutants removal thanks to its unique electronic band structure and excellent physicochemical stability. This paper reviews the recent progress of g-C3N4-based composites as catalysts in various advanced oxidation processes (AOPs), including chemical, photochemical, and electrochemical AOPs. Strategies for enhancing catalytic performance such as element-doping, nanostructure design, and heterojunction construction are summarized in detail. The catalytic degradation mechanisms are also discussed briefly. Keywords: graphitic carbon nitride; aqueous organic pollutants removal; advanced oxidation pro- cesses 1. Introduction In recent years, environmental pollution, especially water pollution, is increasingly Citation: Shen, Y.; Dos santos-Garcia, becoming a major concern worldwide. Many organic pollutions, such as pharmaceuticals and A.J.; Martín de Vidales, M.J. Graphitic personal care products (PPCPs), pesticides, and organic dyes are toxic and refractory [1–4]. Carbon Nitride-Based Composite in Various techniques have been developed to eliminate aqueous organic pollutants (e.g., Advanced Oxidation Processes for extraction, adsorption, biological treatment, and advanced oxidation processes) [5–9].
    [Show full text]
  • Taming Dinitramide Anions Within an Energetic Metal–Organic Framework
    Article pubs.acs.org/cm Taming Dinitramide Anions within an Energetic Metal−Organic Framework: A New Strategy for Synthesis and Tunable Properties of High Energy Materials † † † † ‡ † † Jichuan Zhang, Yao Du, Kai Dong, Hui Su, Shaowen Zhang, Shenghua Li,*, and Siping Pang*, † School of Materials Science & Engineering, Beijing Institute of Technology, Beijing 100081, P. R. China ‡ School of Chemistry, Beijing Institute of Technology, Beijing 100081, P. R. China *S Supporting Information ABSTRACT: Energetic polynitro anions, such as dinitramide − fi fi ion [N(NO2)2 ], have attracted signi cant interest in the eld of energetic materials due to their high densities and rich oxygen contents; however, most of them usually suffer from low stability. Conveniently stabilizing energetic polynitro anions to develop new high energy materials as well as tuning their energetic properties still represent significant challenges. To address these challenges, we herein propose a novel strategy that energetic polynitro anions are encapsulated within energetic cationic metal−organic frameworks (MOFs). We − present N(NO2)2 encapsulated within a three-dimensional (3D) energetic cationic MOF through simple anion exchange. The resultant inclusion complex exhibits a remarkable thermal stability with the onset decomposition temperature of 221 °C, which is, to our knowledge, the highest value known for all dinitramide-based compounds. In addition, it possesses good energetic properties, which can be conveniently tuned by changing the mole ratio of the starting materials. The encapsulated anion can also be released in a controlled fashion without disrupting the framework. This work may shed new insights into the stabilization, storage, and release of labile energetic anions under ambient conditions, while providing a simple and convenient approach for the preparation of new energetic MOFs and the modulation of their energetic properties.
    [Show full text]
  • Comparison of Graphitic Carbon Nitrides Synthetized from Melamine
    materials Article Comparison of Graphitic Carbon Nitrides Synthetized from Melamine and Melamine-Cyanurate Complex: Characterization and Photocatalytic Decomposition of Ofloxacin and Ampicillin Petr Praus 1,2,* , Aneta Smýkalová 1,2 and Kryštof Foniok 1 1 Department of Chemistry VŠB-Technical, University of Ostrava, 17. listopadu 15, 708 00 Ostrava-Poruba, Czech Republic; [email protected] (A.S.); [email protected] (K.F.) 2 Institute of Environmental Technology, VŠB-Technical, University of Ostrava, 17. listopadu 15, 708 00 Ostrava-Poruba, Czech Republic * Correspondence: [email protected] Abstract: Graphitic carbon nitride (g-C3N4, hereafter abbreviated as CN) was prepared by the heating of melamine (CN-M) and melamine-cyanurate complex (CN-MCA), respectively, in air at 550 ◦C for 4 h. The specific surface area (SSA) of CN-M and CN-MCA was 12 m2 g−1 and 225 m2g−1 and the content of oxygen was 0.62 wt.% and 1.88 wt.%, respectively. The band gap energy (Eg) of CN-M was 2.64 eV and Eg of CN-MCA was 2.73 eV. The photocatalytic activity of the CN materials was tested by means of the decomposition of antibiotics ofloxacin and ampicillin under LED irradiation of 420 nm. The activity of CN-MCA was higher due to its high SSA, which was determined based on the physisorption of nitrogen. Ofloxacin was decomposed more efficiently than ampicillin in the presence of both photocatalysts. Citation: Praus, P.; Smýkalová, A.; Foniok, K. Comparison of Graphitic Keywords: graphitic carbon nitride; melamine; melamine-cyanurate complex; photocatalysis; Carbon Nitrides Synthetized from ofloxacin; ampicillin Melamine and Melamine-Cyanurate Complex: Characterization and Photocatalytic Decomposition of Ofloxacin and Ampicillin.
    [Show full text]
  • Simple Synthesis of High Specific Surface Carbon Nitride For
    Wang et al. Nanoscale Research Letters (2018) 13:248 https://doi.org/10.1186/s11671-018-2654-7 NANOEXPRESS Open Access Simple Synthesis of High Specific Surface Carbon Nitride for Adsorption-Enhanced Photocatalytic Performance Jie Wang1,2, Meisheng Li1*, Ming Qian1, Shouyong Zhou1, Ailian Xue1, Lili Zhang1, Yijiang Zhao1* and Weihong Xing2 Abstract TMC-incorporated carbon nitride (CN) with hexagonal and quadrangle honeycomb-like structure and having periodic lattice defects linked by –CONH– bond was synthesized through combining the high calcination with the chemical condensation of melamine and 1,3,5-benzenetricarbonyl trichloride. The obtained CN has a tri-s-triazine ring and benzene ring skeleton, which makes it have excellent mechanical and thermal stability. The BET specific surface area was enhanced to about 125.6 m2/g, and the mean pore size is about 3.43 nm. This CN exhibited an excellent adsorption-enhanced photocatalytic performance. Keywords: Carbon nitride materials, Melamine, Nanoparticles, Sintering Background [4]. Then, the enhancement of specific BET surface for Graphite carbon nitride (g-C3N4), possessing a two-di- g-C3N4 was very important. mensional (2D) nanosheet structure like graphene, has Inspired by the structures of covalent organic frame- attracted much attention recently. The basic skeleton work materials (COFs) [11–16] and their preparation structure of g-C3N4 consists of tri-s-triazine units con- methods [17], we try to combine the high calcination nected with tertiary amino groups, which owns regularly with the chemical condensation to prepare a new kind distributed triangular water-selective permeation nano- of porous TMC-incorporated carbon nitride (CN) linked pores throughout the entire laminar structure.
    [Show full text]
  • Sustainable Applications of Magnetic Nano-Catalysts and Graphitic Carbon Nitrides
    Sustainable Applications of Magnetic Nano-Catalysts and Graphitic Carbon Nitrides Rajender S. Varma Sustainable Technology Division National Risk Management Research Laboratory U. S. Environmental Protection Agency 26 West Martin Luther King Drive, MS 443 Cincinnati, OH-45268 Fax: 513- 569-7677; Tel: 513-487-2701 E-mail: [email protected] •Sustainable synthesis of chemical entities by microwave heating with nano-catalysis in water •Green Chemistry principles are accommodated via multi-faceted approach Minimum Chemical Energy Waste Efficiency Benign Solvents Atom Economy Green Organic Efficient Isolation Chemistry Processes Renewable Feedstock Sustainable Synthetic Safer Method Catalysts & Reagents Microwave Assisted Green Organic Chemistry in Aqueous Medium Seminal Review Articles on these themes summarizing our in-house research: Acc. Chem. Res., 2008, 41, 629; Acc. Chem. Res., 2011, 44, 469-478; Acc. Chem. Res., 2014, 47, 1338-1348 Chem. Soc. Rev., 2008, 37, 1546-1557; Chem. Soc. Rev., 2012, 41, 1559-1584 Chem. Rev., 2016,116, 3722-3811; ACS Sustain. Chem. & Eng., 2016, 4, 5866-5878 Pure App. Chem., 2008, 80, 777-790; Pure App. Chem., 2013, 85, 1703-1710. Curr. Opin. Drug Disc., 2007, 10, 723-737. Green Chem., 1999, 1, 43-55; Green Chem., 2010, 12, 743-754; Green Chem., 2014, 16, 2027-2041. Coord. Chem. Rev., 2015, 291, 68-94; Coord. Chem. Rev., 2015, 287, 137-156. Work During March 2008 to May 2010…. Sugar Plant Extract Vitamins Tea Tea Microwave Wine Water Green Synthesis of Nanomaterials •PROBLEM: Synthesize nanomaterials in a sustainable fashion. •TECHNOLOGY SOLUTION: Learning from Nature- Use the elegance of Riboflavin (Vitamin B2) for redox chemistry. •CURRENT STATUS: Self-assembly of nanoparticles demonstrated Nadagouda & Varma: Green Chemistry, 8, 516, (2006) Green Synthesis of Nanomaterials PROBLEM: Synthesize nanomaterials in a sustainable manner.
    [Show full text]
  • Photocatalysis), and Preparation Techniques of Graphitic Carbon Nitride Nano-Based Particle, and Its Applications Williams Kweku Darkwah and Yanhui Ao*
    Darkwah and Ao Nanoscale Research Letters (2018) 13:388 https://doi.org/10.1186/s11671-018-2702-3 NANO REVIEW Open Access Mini Review on the Structure and Properties (Photocatalysis), and Preparation Techniques of Graphitic Carbon Nitride Nano-Based Particle, and Its Applications Williams Kweku Darkwah and Yanhui Ao* Abstract Graphite carbon nitride (g-C3N4) is well known as one of the most promising materials for photocatalytic activities, such as CO2 reduction and water splitting, and environmental remediation through the removal of organic pollutants. On the other hand, carbon nitride also pose outstanding properties and extensive application forecasts in the aspect of field emission properties. In this mini review, the novel structure, synthesis and preparation techniques of full-bodied g-C3N4-based composite and films were revealed. This mini review discussed contemporary advancement in the structure, synthesis, and diverse methods used for preparing g-C3N4 nanostructured materials. The present study gives an account of full knowledge of the use of the exceptional structural and properties, and the preparation techniques of graphite carbon nitride (g-C3N4) and its applications. Keywords: Photocatalysis, Graphite carbon nitride (g-C3N4), Carbon nitride nano-based particle Introduction Predominantly, wastewater is the major source of pol- The central energy source elated from the extraterrestrial lution, specifically, wastewater produced due to chemical space, solar energy capacities to surpass the almanac industrialization, because this wastewater contains pro- world’s energy request by a large border [1]. Given the nounced concentration of large organic fragments which long forecast era of the Sun, solar energy is also consid- are tremendously poisonous and carcinogenic in nature ered the ultimate renewable source that can be harvested [3].
    [Show full text]
  • Graphitic Carbon Nitride “
    Chem Soc Rev View Article Online REVIEW ARTICLE View Journal | View Issue Graphitic carbon nitride ‘‘reloaded’’: emerging applications beyond (photo)catalysis Cite this: Chem. Soc. Rev., 2016, 45,2308 Jian Liu,*ab Hongqiang Wang*cd and Markus Antoniettia Despite being one of the oldest materials described in the chemical literature, graphitic carbon nitride (g-C3N4) has just recently experienced a renaissance as a highly active photocatalyst, and the metal-free polymer was shown to be able to generate hydrogen under visible light. The semiconductor nature of g-C3N4 has triggered tremendous endeavors on its structural manipulation for enhanced photo(electro)chemical performance, aiming at an affordable clean energy future. While pursuing the stem of g-C3N4 related catalysis (photocatalysis, electrocatalysis and photoelectrocatalysis), a number of emerging intrinsic properties of g-C3N4 are certainly interesting, but less well covered, and we believe that these novel applications outside of conventional catalysis can be favorably exploited as well. Thanks to the general efforts devoted to the exploration and enrichment of g-C3N4 based chemistry, the boundaries of this area have Creative Commons Attribution 3.0 Unported Licence. been possibly pushed far beyond what people could imagine in the beginning. This review strives to cover the achievements of g-C3N4 related materials in these unconventional application fields for depicting the broader future of these metal-free and fully stable semiconductors. This review starts with Received 13th October 2015 the general protocols to engineer g-C3N4 micro/nanostructures for practical use, and then discusses the DOI: 10.1039/c5cs00767d newly disclosed applications in sensing, bioimaging, novel solar energy exploitation including photocatalytic coenzyme regeneration, templating, and carbon nitride based devices.
    [Show full text]
  • 1997-11-12 Cyanide Compounds As Federal Hazardous Air Pollutant
    CYANIDE COMPOUNDS Cyanide compounds are federal hazardous air pollutant and were identified as toxic air contaminants in April 1993 under AB 2728. CAS Registry Numbers: cyanide 57-12-5 CN hydrocyanic acid 74-90-8 HCN Molecular Formulas: CN- HCN The cyanide ion (CN-) combines with other chemicals and exhibits many characteristics that are similar to those of the halogen and azide ions. The molecular weight of cyanide is 26.02. It has an unusually strong tendency to form complex ions with metal ions which may be easily oxidized and thermally unstable. Cyanides are flammable by chemical reaction with heat, moisture, and acid. Many cyanides easily release the very toxic hydrocyanic acid (HCN) which has the odor of bitter almonds. Hydrocyanic acid (hydrogen cyanide) is a liquid at temperatures below 26.5 oC, and its boiling point is so close to room temperature that evaporation of liquid HCN evolves to vapor. Liquid or gaseous HCN is extremely soluble in water. Hydrocyanic acid is miscible with alcohol and slightly soluble in ether. Many organic nitriles can be very reactive under the right conditions and when heated to decomposition or on contact with acid, acid fumes, water or steam, toxic and flammable vapors of CN- are emitted (HSDB, 1991). Physical Properties of Hydrocyanic Acid Synonyms for cyanide: carbon nitride ion (CN1-); cyanide anion; isocyanide Synonyms for hydrocyanic acid: hydrogen cyanide; anammonide; formonitrile; cyclon; prussic acid Hydrocyanic acid Molecular Weight 27.03 Boiling Point: 25.6 oC Melting Point: -13.4 oC Density (liquid): 0.699 at 22 oC Density (gas): 0.901 at 22 oC Vapor Density: 0.94 (air = 1) Vapor Pressure: 630 mm Hg at 20 oC Heat of Fusion: 74.38 Log Octanol/Water Partition Coefficient: 1.07 Conversion Factor (HCN): 1 ppm = 1.1 mg/m3 (HSDB, 1991; Merck, 1989; Sax, 1989; U.S.
    [Show full text]
  • Preparation and Characterization of Metal-Free Graphitic Carbon Nitride Film Photocathodes for Light-Induced Hydrogen Evolution
    Preparation and characterization of Metal-free graphitic Carbon Nitride Film Photocathodes for Light-induced Hydrogen Evolution F. Yang[a], M. Lublow[a], S. Orthmann[a], C. Merschjann[a], T. Tyborski[a], M. Rusu[a], M. Kanis[a], A. Thomas[b], R. Arrigo[c], M. Hävecker[c], Th. Schedel-Niedrig*[a] Very recently, it has been shown that an abundant material, polymeric nanocrystallites. Photo-electrochemical investigations show upon carbon nitride, can produce hydrogen from water under visible-light cathodic polarization light-induced hydrogen evolution for a wide irradiation in the presence of a sacrificial donor [1]. We will present range of proton concentrations in the aqueous electrolyte. here the preparation and characterization of graphitic carbon nitride Additionally, Synchrotron radiation based photoelectron spectroscopy has been applied to study the surface/near-surface chemical (g-C3N4) films on semiconducting substrates by thermal condensation of dicyandiamide precursor under inert gas conditions. Structural and composition of the utilized g-C3N4 film photocathodes. For the first surface morphological studies of the carbon nitride films suggest a time it is shown that g-C3N4 films can be successfully applied as photoelectrochemical material for light induced hydrogen evolution. high porosity of g-C3N4 thin film consisting of a network of -g-C3N4- via thermal polycondensation reaction of cyanamide, dicyandiamide or melamine used as precursors is thoroughly Introduction described in refs. 1 and 19. In the past 3 decades, a variety of inorganic semiconducting, In the present work g-C3N4 films have been deposited onto polymeric and molecular materials have been synthesized as semiconducting substrates by thermal polycondensation of an catalytically active material for hydrogen evolution from water [2-13] organic dicyandiamide precursor.
    [Show full text]
  • Enhanced Dispersibility of Graphitic Carbon Nitride Particles in Aqueous and Organic Media Via a One Pot Grafting Approach
    View metadata, citation and similar papers at core.ac.uk brought to you by CORE provided by MPG.PuRe MPIKG Public Access Author Manuscript Published in final edited form as: Kumru, B., Antonietti, M., & Schmidt, B. V. K. J. (2017). Enhanced Dispersibility of Graphitic Carbon Nitride Particles in Aqueous and Organic Media via a One Pot Grafting Approach. Langmuir, 33(38), 9897-9906. doi:10.1021/acs.langmuir.7b02441. Enhanced Dispersibility of Graphitic Carbon Nitride Particles in Aqueous and Organic Media via a One Pot Grafting Approach Baris Kumru, Markus Antonietti, Bernhard V.K.J. Schmidt ipt Enhanced Dispersibility of Graphitic Carbon Nitride Manuscr · Author · Particles in Aqueous and Organic Media via a One Pot Grafting Approach Baris Kumru, Markus Antonietti, Bernhard V.K.J. Schmidt* Department of Colloid Chemistry, Max Planck Institute of Colloids and Interfaces, Research Campus Golm, 14424 Potsdam (Germany) Max Planck Institute of Colloids and Interfaces Interfaces and Colloids of Institute MaxPlanck KEYWORDS Carbon Nitride, Dispersibility, Grafting ABSTRACT A facile route to synthesize hydrophilically or hydrophobically grafted graphitic carbon nitride (g1CN) is reported. 3or this purpose, functionali0ed olefinic olecules with low poly eri0ation tendency are utili0ed for grafting onto the surface in order to preserve the features of g1CN while i proving its dispersibility. One pot, visible light induced grafting yields highly dispersible g1CNs either in aqueous or organic edia. Moreover, functional groups such as a ine can be introduced, which yields p5 dependent dispersibility in aqueous edia. Co pared with unfunctionali0ed g1CN low sonication ti es are sufficient to redisperse g1CN. In addition, due to increased dispersion stability, higher a ounts of functionali0ed g1CN can be dispersed (up to 107 in aqueous dispersion and 27 in organic dispersion), when co pared to unfunctionali0ed g1CN.
    [Show full text]
  • Dual-Defect-Modified Graphitic Carbon Nitride with Boosted Photocatalytic
    www.nature.com/scientificreports OPEN Dual-defect-modifed graphitic carbon nitride with boosted photocatalytic activity under visible light Hideyuki Katsumata1*, Fumiya Higashi1, Yuya Kobayashi1, Ikki Tateishi2, Mai Furukawa1 & Satoshi Kaneco1,2 The development of photocatalysts that efciently degrade organic pollutants is an important environmental-remediation objective. To that end, we report a strategy for the ready fabrication of oxygen-doped graphitic carbon nitride (CN) with engendered nitrogen defciencies. The addition of KOH and oxalic acid during the thermal condensation of urea led to a material that exhibits a signifcantly higher pseudo-frst-order rate constant for the degradation of bisphenol A (BPA) (0.0225 min−1) compared to that of CN (0.00222 min−1). The enhanced photocatalytic activity for the degradation of BPA exhibited by the dual-defect-modifed CN (Bt-OA-CN) is ascribable to a considerable red-shift in its light absorption compared to that of CN, as well as its modulated energy band structure and more-efcient charge separation. Furthermore, we confrmed that the in-situ-formed cyano groups in the Bt-OA-CN photocatalyst act as strong electron-withdrawing groups that efciently separate and transfer photo-generated charge carriers to the surface of the photocatalyst. This study provides novel insight into the in-situ dual-defect strategy for g-C3N4, which is extendable to the modifcation of other photocatalysts; it also introduces Bt-OA-CN as a potential highly efcient visible-light-responsive photocatalyst for use in environmental-remediation applications. Photocatalytic semiconductor technology is considered to be useful and promising for the remediation of envi- ronmental organic contaminants, because it can efectively decompose pollutants into inorganic compounds, such as CO2 and H2O.
    [Show full text]
  • Synthesis of Ultra-Incompressible Sp3-Hybridized Carbon Nitride
    Synthesis of ultra-incompressible sp3-hybridized carbon nitride Elissaios Stavrou,1 Sergey Lobanov,1, 2 Huafeng Dong,3 Artem R. Oganov,3, 4, 5 Vitali B. Prakapenka,6 Zuzana Kon^opkov´a,7 and Alexander F. Goncharov1, 8 1Geophysical Laboratory, Carnegie Institution of Washington, Washington, D.C. 20015, U.S.A. 2V.S. Sobolev Institute of Geology and Mineralogy, SB RAS, 3 Pr. Ac. Koptyga, Novosibirsk 630090, Russia. 3Department of Geosciences, Center for Materials by Design, Institute for Advanced Computational Science, Stony Brook University, Stony Brook, NY 11794-2100, U.S.A. 4Moscow Institute of Physics and Technology, 9 Institutskiy lane, Dolgoprudny city, Moscow Region, 141700, Russian Federation 5School of Materials Science, Northwestern Polytechnical University, Xi'an,710072, China 6Center for Advanced Radiation Sources, University of Chicago, Chicago, IL 60637, USA 7DESY Photon Science, D-22607 Hamburg, Germany 8Key Laboratory of Materials Physics and Center for Energy Matter in Extreme Environments, Institute of Solid State Physics, Chinese Academy of Sciences, Hefei 230031, China arXiv:1412.3755v1 [cond-mat.mtrl-sci] 11 Dec 2014 1 Search of materials with C-N composition hold a great promise in creating materials which would rival diamond in hardness due to the very strong and rel- atively low-ionic C-N bond. Early experimental and theoretical works on C-N compounds were based on structural similarity with binary A3B4 structural- types; however, the synthesis of C3N4 remains elusive. Here we explored an unbiased synthesis from the elemental materials at high pressures and temper- atures. Using in situ synchrotron X-ray diffraction and Raman spectroscopy we demonstrate synthesis of highly incompressible Pnnm CN compound with sp3 hybridized carbon is synthesized above 55 GPa and 7000 K.
    [Show full text]