Morphology Controlled Synthesis of SnS2 Nanomaterial for Promoting ...
Morphology Controlled Synthesis of SnS2 Nanomaterial for Promoting Photocatalytic Reduction of Aqueous Cr(VI) under Visible Light Chanchal Mondal,a Mainak Ganguly,a Jaya Pal,a Anindita Roy,a Jayasmita Jana,a Tarasankar Pal*,a a
Department of Chemistry, Indian Institute of Technology, Kharagpur-721302, India E-mail: [email protected]
Experimental section
Materials: All the reagents were analytically pure. SnCl2, thioacetamide, K2Cr2O7 purchased from E-Merck were used as received. Double distilled water was used to prepare all the stock solutions. Beakers and other glasswares (capacity 15 mL) were purchased from Blue Star India and they were cleaned with aqua regia, water and dried prior to their use. Analytical Instrument: The chemical compositions of the nanomaterials were investigated by Powder X-ray diffraction (XRD). It was recorded using a PW1710 diffractometer, a Philips, Holland, instrument. The XRD data were verified by taking (JCPDS) software. Reflectance spectra were carried out using DRS (Diffuse Reflectance Spectra) mode by a Cary model 5000 UV-vis-NIR spectrophotometer. Raman spectra were carried out with a Renishaw Raman Microscope which is equipped with a He-Ne laser excitation ource of emitting wave length 633 nm and a peltier cooled (-70°C) charge coupled device camera (CCD). The morphology was examined using Field emission scanning electron microscopy (FESEM, supra 40, Carl Zeiss Pvt. Ltd. instrument) and an energydispersive X-ray microanalyzer (Oxford ISI 300) was attached to the scanning electron microscope for compositional analysis. Transmission electron microscopy (TEM) was done with an H-9000 NAR instrument, Hitachi, using an accelerating voltage of 300 kV to understand the morphology, SAED pattern and fringe spacing. The chemical state of the surface of the nanomaterial was obtained X-ray photoelectron spectroscopy (XPS) measurements, carried out by a VG Scientific Escalab MK II spectrometer equipped with a Mg Kr excitation source (1253.6 eV) and a five-channeltron detection system. The Brunauer-Emmett-Teller (BET) surface area and pore size distribution were performed with an accelerated surface area and porosimetry system (ASAP 2020 V3.01 G) from N2 adsorption-desorption isotherms. All absorption spectra for the dye degradation were recorded in a chemito spectrophotometer (India) and taking the solutions in a 1 cm quartz cuvette.
Figure S1: FESEM images of the SnS2 nanoflower showing the thickness of the sheets.
Figure S2: FESEM images of the nanoyarns obtained at different growth stages: (a) 1 h, (b) 2 h; SEM images of the nanoflowers obtained at different growth stages: (a) 1 h, (b) 2 h;
Figure S3: EDX spectrum of SnS2 nanoflower.
0.6
0.6
a 0.5
Absorbance (a.u.)
Absorbance (a.u.)
Blank test Without visible light exposure 0.4 Initial 2 hr 6 hr 10 hr
0.2
0.0
b
Blank test Without catalyst
0.4 0.3
Initial 15 h
0.2 0.1 0.0
300
400
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Wavelength (nm)
600
700
300
400
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Wavelength (nm)
Figure S4: (a) Blank test carried out for dichromate (2 x 10-4 M) in presence of catalyst without visible light exposure, (b) in absence of catalyst under visible light exposure.
1.0
1.0
a
pH = 1.5 0 min 15 min 25 min
Absorbance (a.u.)
Absorbance (a.u.)
0.6
b
pH = 3.5 0.8
0.8
0.4
0.2
0 min 15 min 25 min 35 min 45 min
0.6
0.4
0.2
0.0
0.0
300
250 300 350 400 450 500 550 600 650 700
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Wavelength (nm)
Wavelength (nm)
600
700
1.0
C Absorbance (a.u.)
0.8
pH = 5.5 0 min 15 min 25 min 35 min 45 min 55 min
0.6
0.4
0.2
0.0 300
400
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700
Wavelength (nm)
Figure S5. effect of initial pH on the photocatalytic reduction of Cr(VI) under visible light in presence of SnS2 nanoflower.
8000
Intensity (a.u.)
7000
a. Nanoyarn b. Nanoflower
6000 5000 4000 3000 2000
b a
1000 10
20
30
40
50
60
70
80
2θ (degree)
Figure S6: XRD pattern of the SnS2 nanomaterial (a. nanoyarn, b. nanoflower) after photocatalytic reduction of Cr(VI).
Department of Chemistry, Indian Institute of Technology, Kharagpur-721302, India E-mail: [email protected]
Experimental section
Materials: All the reagents were analytically pure. SnCl2, thioacetamide, K2Cr2O7 purchased from E-Merck were used as received. Double distilled water was used to prepare all the stock solutions. Beakers and other glasswares (capacity 15 mL) were purchased from Blue Star India and they were cleaned with aqua regia, water and dried prior to their use. Analytical Instrument: The chemical compositions of the nanomaterials were investigated by Powder X-ray diffraction (XRD). It was recorded using a PW1710 diffractometer, a Philips, Holland, instrument. The XRD data were verified by taking (JCPDS) software. Reflectance spectra were carried out using DRS (Diffuse Reflectance Spectra) mode by a Cary model 5000 UV-vis-NIR spectrophotometer. Raman spectra were carried out with a Renishaw Raman Microscope which is equipped with a He-Ne laser excitation ource of emitting wave length 633 nm and a peltier cooled (-70°C) charge coupled device camera (CCD). The morphology was examined using Field emission scanning electron microscopy (FESEM, supra 40, Carl Zeiss Pvt. Ltd. instrument) and an energydispersive X-ray microanalyzer (Oxford ISI 300) was attached to the scanning electron microscope for compositional analysis. Transmission electron microscopy (TEM) was done with an H-9000 NAR instrument, Hitachi, using an accelerating voltage of 300 kV to understand the morphology, SAED pattern and fringe spacing. The chemical state of the surface of the nanomaterial was obtained X-ray photoelectron spectroscopy (XPS) measurements, carried out by a VG Scientific Escalab MK II spectrometer equipped with a Mg Kr excitation source (1253.6 eV) and a five-channeltron detection system. The Brunauer-Emmett-Teller (BET) surface area and pore size distribution were performed with an accelerated surface area and porosimetry system (ASAP 2020 V3.01 G) from N2 adsorption-desorption isotherms. All absorption spectra for the dye degradation were recorded in a chemito spectrophotometer (India) and taking the solutions in a 1 cm quartz cuvette.
Figure S1: FESEM images of the SnS2 nanoflower showing the thickness of the sheets.
Figure S2: FESEM images of the nanoyarns obtained at different growth stages: (a) 1 h, (b) 2 h; SEM images of the nanoflowers obtained at different growth stages: (a) 1 h, (b) 2 h;
Figure S3: EDX spectrum of SnS2 nanoflower.
0.6
0.6
a 0.5
Absorbance (a.u.)
Absorbance (a.u.)
Blank test Without visible light exposure 0.4 Initial 2 hr 6 hr 10 hr
0.2
0.0
b
Blank test Without catalyst
0.4 0.3
Initial 15 h
0.2 0.1 0.0
300
400
500
Wavelength (nm)
600
700
300
400
500
600
700
Wavelength (nm)
Figure S4: (a) Blank test carried out for dichromate (2 x 10-4 M) in presence of catalyst without visible light exposure, (b) in absence of catalyst under visible light exposure.
1.0
1.0
a
pH = 1.5 0 min 15 min 25 min
Absorbance (a.u.)
Absorbance (a.u.)
0.6
b
pH = 3.5 0.8
0.8
0.4
0.2
0 min 15 min 25 min 35 min 45 min
0.6
0.4
0.2
0.0
0.0
300
250 300 350 400 450 500 550 600 650 700
400
500
Wavelength (nm)
Wavelength (nm)
600
700
1.0
C Absorbance (a.u.)
0.8
pH = 5.5 0 min 15 min 25 min 35 min 45 min 55 min
0.6
0.4
0.2
0.0 300
400
500
600
700
Wavelength (nm)
Figure S5. effect of initial pH on the photocatalytic reduction of Cr(VI) under visible light in presence of SnS2 nanoflower.
8000
Intensity (a.u.)
7000
a. Nanoyarn b. Nanoflower
6000 5000 4000 3000 2000
b a
1000 10
20
30
40
50
60
70
80
2θ (degree)
Figure S6: XRD pattern of the SnS2 nanomaterial (a. nanoyarn, b. nanoflower) after photocatalytic reduction of Cr(VI).
