Tin(II) Antimonates with Adjustable Compositions: Effects of Band‐Gaps and Nanostructures on Visible‐Light‐Driven Photocatalytic H₂ Evolution

Abstract

A series of tin(II)–antimonate photocatalysts with varied Sn content were prepared by altering the ion‐exchange time and reaction temperature to control their physicochemical properties, especially their band‐gaps and nanostructures. Furthermore, the effect of these catalysts on visible‐light‐driven photocatalytic H2‐evolution was also investigated. With an increase in Sn content, the narrowed band‐gaps enhanced the absorption of photons to excite the photogenerated charge carriers. A decrease in nanocrystal size approaching stoichiometric compositions impeded the recombination of the photogenerated charge carriers; the increased surface areas and pore volumes, owing to the nanostructural transformation, accelerated the redox reactions. Consequently, the photocatalytic activities gradually improved and the highest rate was observed for stoichiometric Sn2Sb2O7. As a result, the as‐prepared tin(II) antimonates—especially Sn2Sb2O7—were confirmed to be stable and efficient photocatalysts for visible‐light‐driven H2 evolution. Moreover, the activities of these photocatalysts could be improved by tuning their physicochemical properties to jointly optimize all of the processes in the photocatalytic reaction.

Urea-derived graphitic carbon nitride (u-g-C3N4) films with highly enhanced antimicrobial and sporicidal activity

“…Bandgap values are estimated from diffuse reflectance data using Kubelka-Munk theory. [34, 35] X-ray photoelectron spectroscopy was conducted on a PHI 5000 Versaprobe II Scanning ESCA microprobe using a monochromatic Al K α X-ray source (1486.6 eV). The base vacuum in the chamber was better than 1.5 × 10 −10 torr.…”

Preparation and characterization of photoactive antimicrobial graphitic carbon nitride (g-C3N4) films

“…Bandgap values are estimated using Kubelka-Munk theory. 32, 33 Raman data was collected on a Thermo Nicolet 870 instrument that was coupled to an FT-Raman module. X-ray photoelectron spectroscopy was conducted on a PHI 5000 Versaprobe II Scanning ESCA microprobe using a monochromatic Al K α X-ray source (1486.6 eV).…”

Structure defects in g-C3N4 limit visible light driven hydrogen evolution and photovoltage

“…24,25 Powder X-ray diffraction (XRD) patterns were measured with a Scintag XRD (Cu Ka: l ¼ 0.154 nm) at À45 kV and 40 mA, equipped with divergence (2 mm), scatter (4 mm), column scatter (0.5 mm), and receiving (0.2 mm) slits. Tauc plots were obtained through two formulae: R ¼ 10 ÀA and F(R) ¼ (1 À R) 2 /(2R), where A, R and F(R) stand for absorbance, relative reectance and Kubelka-Munk function, respectively.…”

“…Tauc plots were obtained through two formulae: R ¼ 10 ÀA and F(R) ¼ (1 À R) 2 /(2R), where A, R and F(R) stand for absorbance, relative reectance and Kubelka-Munk function, respectively. 24,25 Powder X-ray diffraction (XRD) patterns were measured with a Scintag XRD (Cu Ka: l ¼ 0.154 nm) at À45 kV and 40 mA, equipped with divergence (2 mm), scatter (4 mm), column scatter (0.5 mm), and receiving (0.2 mm) slits. Fourier transform infrared reection (FTIR) spectra were obtained with the IR spectrometer (BRUKER-Alpha) and soware (OPUS 6.5).…”