Electronic Supplementary Material (ESI) for CrystEngComm. This journal is © The Royal Society of Chemistry 2021 Electronic supplementary Information: 3D/2D Bi2S3/SnS2 Heterostructures: Superior Charge Separation and Enhanced Solar Light Driven Photocatalytic Performance Sumana Paul1,3†, Dulal Barman1⁋†, Chandra Chowdhury2, P. K. Giri3 and Subodh Kumar De1* 1Scool of Materials Sciences, Indian Association for the Cultivation of Science, Jadavpur, Kolkata- 700032, India 2Institute of Catalysis Research and Technology (IKFT), Karlsruhe Institute of Technology (KIT), Eggenstein-Leopoldshafen, Germany. 3Department of Physics, Indian Institute of Technology Guwahati, Guwahati 781039, India. *E-mail: [email protected] †Authors Contributed Equally ⁋ Present Address: Department of Physics, Balurghat College, Balurghat, Dakshin Dinajpur 733101, India. (A) (B) (C) (D) (C) Fig. S1. (A) TEM image of BSS2 heterostructure. (B) A closer view of densely SnS2 decorated Bi2S3 urchine. (C) HRTEM image of a nanorod fully covered with SnS2 nanosheets. (D) FFT pattern obtained from the yellow square region showing planes of both Bi2S3 and SnS2 where (011), (210) correspond of planes Bi2S3 and (012), (001) corresponds to planes of SnS2. (A) (B) (C) (D) Fig. S2. (A) Large area TEM image of SnS2 nanosheets. (B) A closer view of a few nanosheets. (C) HRTEM image obtained from a single SnS2 nanosheet. (D) FFT pattern obtained from the blue square region showing the planes (100), (1 20),̅ (21 ̅0) of SnS2. (B) (A) Bi (C) Sn (D) S (E) Fig. S3. TEM image (A) of the Bi2S3/SnS2 heterostructure (BSS1.5) and the corresponding EDS mapping of Bi (B, magenta), Sn (C, cyan) and S (D, yellow) and (E) the EDS scan. (A) (B) Bi (C) Sn (D) S (E) Fig. S4. TEM image (A) of the Bi2S3/SnS2 heterostructure (BSS2) and the corresponding EDS mapping of Bi (B, magenta), Sn (C, cyan) and S (D, yellow) and (E) the EDS scan. BSS1 Bi S Time (min) 0 min Time (min) 0 min 2 3 (B) 1 min (A) 1 min 2 min 2 min 3 min 3 min 4 min 4 min 5 min 5 min Absorbance (a.u.) Absorbance (a.u.) 450 500 550 600 650 450 500 550 600 Wavelength (nm) Wavelength (nm) BSS2 Time (min) 0 min BSS1.5 0 min Time (min) (D) 1 min (C) 1 min 2 min 2 min 3 min 3 min 4 min 4 min 5 min 5 min Absorbance (a.u.) Absorbance (a.u.) 450 500 550 600 650 450 500 550 600 650 Wavelength (nm) Wavelength (nm) Fig. S5. Photocatalytic degradation of RhB dye in presence of (A) Bi2S3 urchines, (B) BSS1, (C) BSS1.5 and (D) BSS2 heterostructure under solar simulator. (B) (A) Bi S BSS1 0 min 2 3 0 min Time (min) Time (min) 5 min 5 min 10 min 10 min 15 min 15 min 20 min 20 min 25 min 25 min 30 min 30 min Absorbance (a.u.) Absorbance (a.u.) 500 550 600 650 700 750 500 550 600 650 700 750 Wavelength (nm) Wavelength (nm) (C) BSS1.5 (D) BSS2 0 min 0 min Time (min) Time (min) 5 min 5 min 10 min 10 min 15 min 15 min 20 min 20 min 25 min 25 min 30 min 30 min Absorbance (a.u.) Absorbance (a.u.) 500 550 600 650 700 750 500 550 600 650 700 750 Wavelength (nm) Wavelength (nm) Fig. S6. Photocatalytic degradation of MB dye in presence of (A) Bi2S3 urchines, (B) BSS1, (C) BSS1.5 and (D) BSS2 heterostructures under solar simulator. BSS1 Bi2S3 Time (min) Time (min) 0 min (B) 0 min (A) 10 min 10 min 20 min 20 min 30 min 30 min 40 min 40 min 50 min 50 min 60 min 60 min Absorbance (a.u.) Absorbance (a.u.) 400 500 600 700 400 500 600 700 Wavelength (nm) Wavelength (nm) BSS1.5 BSS2 Time (min) 0 min 0 min (C) (D) Time (min) 10 min 10 min 20 min 20 min 30 min 30 min 40 min 40 min 50 min 50 min 60 min 60 min Absorbance (a.u.) Absorbance (a.u.) 400 500 600 700 400 500 600 700 Wavelength (nm) Wavelength (nm) Fig. S7. Detection of Cr(VI) in presence of (A) Bi2S3 urchines, (B) BSS1, (C) BSS1.5 and (D) BSS2 heterostructure under solar simulator. (B) (A) BSS2 (B) BSS1.5 Intensity (a.u.) BS 10 20 30 40 50 60 70 2q (degree) (C) (D) Fig. S8 . XRD pattern of (A) pure Bi2S3, BSS1.5 and BSS2 heterostructures after photocatalytic activity and SEM images of (B) pure Bi2S3, (C) BSS1.5 and (D) BSS2 heterostructures after photocatalytic activity. BS BSS1 BSS1.5 BSS2 PL Intensity (a. u.) (a. Intensity PL 400 450 500 550 600 Wavelength (nm) Fig. S9. Room temperature PL spectra of different photocatalysts. Adsorption 35 Bi2S3 300 Adsorption BSS1.5 Desorption Desorption ) 2 ) 30 Surface area= 23.54 m /g 250 Surface Area = 259.24 m2/g /gm /gm 3 3 (A) (B) cm cm 200 ( 25 ( 3.0 BSS1.5 30 20 BS 150 ) Pore Diameter = 2 nm to 10 nm ) 2.5 Pore Diameter = 2 nm to 7 nm 25 /g 2 /g 2 2.0 m 20 ( m 100 15 ( 1.5 15 1.0 10 50 10 0.5 5 Pore area Volume Absorbed Absorbed Volume Volume Absorbed Absorbed Volume Pore area 0.0 0 5 0 5 10 15 20 25 0 0 5 10 15 20 25 Pore Diameter (nm) Pore Diameter (nm) 0.0 0.2 0.4 0.6 0.8 1.0 0.0 0.2 0.4 0.6 0.8 1.0 Relative Pressure (P/P ) 0 Relative Pressure (P/P0) 60 Adsorption BSS2 Desorption ) 50 Surface Area=41.95 m2/g /gm 3 (C) 40 cm ( 30 5 BSS2 Pore Diameter = 3 nm to 14 nm ) 4 /g 2 20 3 m ( 2 10 1 Volume Absorbed Absorbed Volume Pore area 0 0 0 5 10 15 20 25 Pore Diameter (nm) 0.0 0.2 0.4 0.6 0.8 1.0 Relative Pressure (P/P0) Fig. S10. BET adsorption–desorption isotherms and the pore-size distribution (inset) of (A) pure Bi2S3, (B) BSS1.5 and (C) BSS2 heterostructures. (B) BS (A) BS 0 min BSS1 10 min BSS1.5 20 min 30 min PL Intensity (a.u.) Intensity PL PL Intensity (a.u.) Intensity PL 400 450 500 400 450 500 Wavelength (nm) Wavelength (nm) (C) BSS1 (D) BSS1.5 0 min 0 min 10 min 10 min 20 min 20 min 30 min 30 min PL Intensity (a. u.) (a. Intensity PL PL Intensity (a.u.) Intensity PL 400 450 500 400 450 500 Wavelength (nm) Wavelenth (nm) Fig. S11 . (A) Determination of hydroxyl radicals on the surface of different photocatalysts under solar light irradiation for 30 min using photoluminescence spectra of TAOH (λ=315 nm) at 425 nm. Photoluminescence spectra of the solar light irradiated (B) BS, (C) BSS1, (D) BSS1.5 suspensions in terephthalic acid at different irradiation time. Table S1: Relative band position of the Bi2S3 and SnS2. Semiconductor Electronegativity of the Optical Valance Band Conduction Band semiconductor (eV) band gap Position (eV) Position (eV) (eV) (Experiment) Experiment Theory Experiment Theory Bi2S3 5.28 1.2 1.38 1.60 0.18 0.12 SnS2 6.33 2.48 3.07 2.05 0.59 0.55 Scheme 1. Relative band alignment of Bi2S3 and SnS2. .