REVIEW Black Phosphorus www.advenergymat.de Applications of Phosphorene and Black Phosphorus in Energy Conversion and Storage Devices Jinbo Pang, Alicja Bachmatiuk, Yin Yin, Barbara Trzebicka, Liang Zhao, Lei Fu, Rafael G. Mendes, Thomas Gemming, Zhongfan Liu, and Mark H. Rummeli* to the extreme high-pressure heating con- The successful isolation of phosphorene (atomic layer thick black phos- ditions required for its synthetic prepara- phorus) in 2014 has currently aroused the interest of 2D material researchers. tion, as well as a lack of knowledge of its applications. Then, a decade ago, Park In this review, first, the fundamentals of phosphorus allotropes, phos- and Sohn[2] exploited high-energy ball phorene, and black phosphorus, are briefly introduced, along with their struc- milling to fabricate black phosphorus as tures, properties, and synthesis methods. Second, the readers are presented anode materials for rechargeable lithium with an overview of their energy applications. Particularly in electrochemical ion batteries. Eventually, bulk crystals of energy storage, the large interlayer spacing (0.53 nm) in phosphorene allows black phosphorus were successfully fab- the intercalation/deintercalation of larger ions as compared to its graphene ricated in large batches by Nilges and co-workers[3–5] using a chemical vapor counterpart. Therefore, phosphorene may possess greater potential for high transport approach. This prompted its electrochemical performance. In addition, the status of lithium ion batteries exploration in energy-related devices such as well as secondary sodium ion batteries is reviewed. Next, each applica- as secondary ion batteries, supercapaci- tion for energy generation, conversion, and storage is described in detail tors, and solar cells. with milestones as well as the challenges. These emerging applications Few layer or monolayer black phos- phorus possess a larger specific area than include supercapacitors, photovoltaic devices, water splitting, photocatalytic its 3D parents. Early works termed the hydrogenation, oxygen evolution, and thermoelectric generators. Finally material as nanosheets, ultrathin,[6,7] atomic the fast-growing dynamic field of phosphorene research is summarized and layer thin,[8] few layer,[9] and monolayer perspectives on future possibilities are presented calling on the efforts of black phosphorus.[10] Thus, we will need to chemists, physicists, and material scientists know the correct terminology from a strict chemical view. The word suffix ene is usu- ally adopted for naming a molecular struc- 1. Introduction ture which consists of π electrons such as graphene. But there is no π electrons in black phosphorus, so that Black phosphorus was first synthesized by Bridgman in 1914[1] International Union of Pure And Applied Chemistry (IUPAC) but has been less intensively studied in the past century due name will be 2D phosphorane as suggested by Castro Neto Dr. J. Pang, Prof. A. Bachmatiuk, Y. Yin, Dr. R. G. Mendes, Prof. A. Bachmatiuk, Prof. B. Trzebicka, Prof. M. H. Rummeli Dr. T. Gemming, Prof. M. H. Rummeli Centre of Polymer and Carbon Materials The Leibniz Institute for Solid State and Materials Research Dresden Polish Academy of Sciences (CMPW PAN) (IFW Dresden) ul. M. Curie-Sklodowskiej 34, Zabrze PL-41-819, Poland Helmholtzstr. 20, Dresden D-01069, Germany Prof. L. Fu E-mail: [email protected] College of Chemistry and Molecular Science Prof. A. Bachmatiuk, L. Zhao, Dr. R. G. Mendes, Prof. Z. Liu, Wuhan University Prof. M. H. Rummeli Wuhan 430072, China Key Laboratory of Advanced Carbon Materials and Wearable Prof. Z. Liu Energy Technologies of Jiangsu Province Center for Nanochemistry (CNC) Soochow University Beijing Science and Engineering Center for Nanocarbons Suzhou 215006, China College of Chemistry and Molecular Engineering Prof. A. Bachmatiuk, L. Zhao, Dr. R. G. Mendes, Prof. Z. Liu, Peking University Prof. M. H. Rummeli Beijing 100871, China Soochow Institute for Energy and Materials InnovationS (SIEMIS) School of Energy Optoelectronics and Energy & Collaborative Innovation Center of Suzhou Nano Science and Technology Soochow University Suzhou 215006, China DOI: 10.1002/aenm.201702093 Adv. Energy Mater. 2017, 1702093 1702093 (1 of 43) © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim www.advancedsciencenews.com www.advenergymat.de and co-workers[11] and Martel and co-workers.[12] But gradually over time, phosphorene[13] became accepted by the community Jinbo Pang is presently a post- and we will use this terminology, that of phosphorene for mon- doctoral fellow in the Leibniz olayer or few layer black phosphorus in this review. Institute for Solid State and Early in 2014, the theoretical work of few layer black phos- Materials Research Dresden, phorus pioneered by Castro Neto and co-workers[14] showed Germany. He received its band gap with tunable capability under strain. Later, phos- M. Eng. from the Institute phorene, a monolayer sheet of black phosphorus, was afterward of Photoelectronics, Nankai successfully experimentally exfoliated in 2014 by Zhang and co- University, China in 2011 and workers[8] as well as Ye and co-workers[13] in which they imple- Ph.D. in Materials Science mented the scotch-tape microcleavage method, which is well from Dresden University of known for graphene isolation. After these pioneering works, Technology (TU Dresden) in numerous 2D research teams began rapidly exploiting this new 2017. His research focuses material over the previously intensively studied 2D materials on the synthesis, device fabrication, and energy device such as graphene,[15–22] transition metal dichalcogenides,[23–30] applications of graphene and other novel 2D materials as hexagonal boron nitride,[31–38] MXenes,[39–47] and silicene.[48–52] well as characterizations with electron microscopy. Since energy storage and conversion have become so crucial for the future of consumer electronics, electrical vehicles, and grid storage, electrochemical energy devices based on phos- Alicja Bachmatiuk currently phorene are intensively studied. We therefore review the work heads the graphene group at thus far conducted on phosphorene in energy applications such Polish Academy of Sciences as secondary ion batteries, supercapacitors, solar cells, photo- (CMPW PAN) in Zabrze catalysts for solar fuel production such as hydrogen from water and looks after a double Cs splitting and hydrocarbon from carbon dioxide reduction, the corrected TEM in Wroclaw oxygen evolution reaction and hydrogenation, and thermoelec- Research Centre EIT+, Poland. tric power generators. In the review, the concepts and chal- She is a guest professor lenges in energy devices are presented and we hope to inspire at the Soochow Institute readers toward the future possibilities and opportunities with for Energy and Materials this material. We begin with a look at the fundamentals of InnovationS (SIEMIS), phosphorene. Soochow University. She obtained her Ph.D. in chemistry at Szczecin University and joined the IFW Dresden with a Humboldt postdoctoral 1.1. Phosphorus Allotropes fellowship. Phosphorus is an earth-abundant element from group 15 in the period table of elements (also termed pnictogen group). Mark H. Rummeli heads the Because phosphorus easily loses electrons resulting in high electron microscopy labs reactivity, straightforward natural access of the free element on at the Soochow Institute Earth is yet to be reported. Typically it exists in an oxidized state for Energy and Materials InnovationS (SIEMIS), within phosphate rocks, e.g., Ca3(PO4)2. Phosphorus has four allotropes (Figure 1), namely, red, Soochow University. He white, violet, and black phosphorus, named according to their also oversees the gas appearance. White phosphorus and red phosphorus are the two sensor laboratory at Polish major allotropes. White phosphorus, consisting of tetrahedral Academy of Sciences, Zabzre. He earned his Ph.D. P4 molecules, can be easily obtained by the sintering of mineral phosphate rocks in the presence of coke and silica. It is reac- from London Metropolitan tive and volatile, and ignites in air at 34 °C; hence, it requires University and then worked as a Research Fellow at the German Aerospace Center. His water sealing for storage. Red phosphorus is a derivative of P4 wherein a PP bond dissociates and forms a new bond with an research focuses on the growth mechanisms of nanostruc- tures and their functionalization and their application in adjacent tetrahedron P4; this eventually yields a chained struc- ture similar to that of a polymer. Amorphous red phosphorus electronic, biomedical, and energy storage. can be prepared by heating white phosphorus in N2 at ≈300 °C or exposing it to sunlight. Further heating yields crystalline red phosphorus. Violet phosphorus can be synthesized by the long- time annealing of red phosphorus at 550 °C with the assistance from white phosphorus under extreme high-pressure heating of molten lead. conditions (1.2 GPa at 200 °C).[1] Black phosphorus bulk crys- Black phosphorus is the thermodynamically stable allotrope. tals consist of stacked layer structures, termed phosphorene.[53] Analogous to graphite in appearance, black phosphorus is shiny The interlayer interactions between these stacking layers are black and has good electrical conductance. It can be produced comparable to van der Waals interactions,[54–56] which can be Adv. Energy Mater. 2017, 1702093 1702093 (2 of 43) © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim www.advancedsciencenews.com www.advenergymat.de