Fabrication of Sulfur Defect Rich ZnIn₂S₄/SnSe₂ Photocatalyst with Ohmic Junction for Efficient Water to Hydrogen Energy Conversion

Abstract

The development of a noble‐metal‐free cocatalyst is of great significance for boosting photocatalytic H2 evolution performance. Herein, SnSe2 is developed as a cocatalyst to in situ attachment on the surface of sulfur defect rich ZnIn2S4 (Vs‐ZIS) via a simple hydrothermal method. Owing to the intimate atomic‐level interface and the different work function between Vs‐ZIS and SnSe2, a particular Ohmic junction with internal electric field is formed in Vs‐ZIS/SnSe2, which facilitates the electrons in Vs‐ZIS transfer to SnSe2 and participate in H2 evolution reaction rapidly. Moreover, the abundant S vacancies also benefit the separation of photocarriers in Vs‐ZIS/SnSe2. The optimized Vs‐ZIS/SnSe2 photocatalyst performs a high H2 evolution rate of 29.34 mmol h−1 g−1 under visible light (λ > 420 nm) and an apparent quantum efficiency of 12.25% at 420 nm. Herein, constructive model on developing effective cocatalyst is afforded, and expediting photocarriers transfer through interfacial modulating.

Selective Oxidation of 5-Hydroxymethyl Furfural Coupled with H2 Production over Surface Sulfur Vacancy-Rich Zn3In2S6/Bi2MoO6 Heterojunction Photocatalyst

“…The EPR spectra were recorded to further verify if V S were successfully introduced into the ZIS-V S and ZIS-V S /BMO samples. As shown in Figure d, the above samples display typical single Lorentzian lines in the same magnetic field region with a g -value of 2.007, which could be attributed to the unpaired electrons on the sulfur atoms . The ZIS sample presented a weak EPR signal response.…”

“…As shown in Figure 1d, the above samples display typical single Lorentzian lines in the same magnetic field region with a g-value of 2.007, which could be attributed to the unpaired electrons on the sulfur atoms. 17 The ZIS sample presented a weak EPR signal response. In comparison, the EPR peaks centered at g = 2.007 presented significant enhancement in the ZIS-V S and ZIS-V S /BMO samples, revealing the significantly increased sulfur vacancy concentration in those samples.…”

Recent progress in defect‐engineered metal oxides for photocatalytic environmental remediation

“…These defects in photocatalytic hybrid materials might be point defects, volume defects, or the terminations of line defects and planar defects, similar to the surface defects. 44 Defect-engineered photocatalysts have been widely used in various photocatalytic applications such as organic pollutants' degradation, 56,57 pharmaceutical degradation, 58,59 CO 2 reduction, 60,61 H 2 evolution, 62,63 N 2 reduction, 64,65 etc. which directly focus on environmental remediation and sustainability, providing a large scope of development of defect engineering in materials.…”

Construction of core–shell CoSe2/ZnIn2S4 heterostructures for efficient visible-light-driven photocatalytic hydrogen evolution

“…It has been reported that metal selenides could accelerate the charge transfer of the hydrogen evolution reaction due to their lower electrical resistance, indicating that metal selenides are promising catalysts. 6,26,27 Recently, it was reported that metal selenides ZnSe, 28 SnSe 2 , 29 NiSe 2 , 16 and MoSe 2 30 were used to form composites with ZnIn 2 S 4 to promote charge migration, thus improving the activity of photocatalytic hydrogen evolution. The inherent properties of CoSe 2 endowed it with high electronic conductivity and proton adsorption ability, while its low cost and stable chemical properties made it a potential substitute for noble metals.…”