An efficient method to enhance the stability of sulphide semiconductor photocatalysts: a case study of N-doped ZnS

Abstract

Reducing the oxidative capacity of holes (h(+)) in the valence band (VB) of ZnS is one of the most effective ways to prevent the photocatalyst from photocorrosion. In this work, ZnS doped only with nitrogen was prepared for the first time by nitriding ZnS powder in an NH3 atmosphere. We demonstrate theoretically and experimentally that the valence band maximum (VBM) rises obviously by N-doping in ZnS, suggesting the reduction of the oxidative capacity of holes (h(+)) in the valence band. The theoretically predicted band structures were further verified by valence band X-ray photoelectron spectroscopy (VB XPS) and Mott-Schottky measurements. The as-prepared N-doped ZnS exhibited an outstanding stable capability for photocatalytic hydrogen evolution from water under simulated sunlight irradiation for 12 h. However, pristine ZnS showed no capability and was seriously photocorroded under the same conditions.

Kinetic Competition between Water‐Splitting and Photocorrosion Reactions in Photoelectrochemical Devices

“…[47] The impacto ft he evolving corrosion layer wasn ot taken into account in our model. ZnS is known to quickly photocorrode in PEC water-splittinge nvironments, [48,53] whichi s consistentwith our predictions (PS < 0.004).…”

Semiconductor-based photocatalysts for photocatalytic and photoelectrochemical water splitting: will we stop with photocorrosion?

“…In this regard, Zhou et al prepared N-doped ZnS by nitriding ZnS powder in an NH 3 atmosphere. 96 DFT calculations revealed the VBM of ZnS was increased aer nitrogen heteroatoms occupied the S sites, but the CBM still basically consisted of the Zn 4s states and small S 3p states with a small position change. That is, the CB electrons still maintained high reduction ability while the oxidative capacity of holes was weakened, which effectively inhibited the holeinduced photocorrosion of ZnS, resulting in less dissociation in aqueous solution for the N-doped ZnS sample.…”

Facile preparation and characterization of a novel visible-light-responsive Rb2HgI4 nanostructure photocatalyst

“…Semiconductor-based photocatalysts are one of the most successful strategies for wastewater/water treatment owing to their high potential and high efficiency in eliminating toxic organic pollutants utilizing solar light. [8][9][10][11] The structural, electronic, and optical properties of the material must be carefully studied to promote efficient semiconductor-based photocatalysts for the photodegradation of contaminants in wastewater/water. Commonly, various characteristics, for instance the selection of semiconductor materials, morphological architecture, and surface features, should be considered when designing efficient and stable visible-light-sensitive photocatalysts.…”