Photocatalytic and Photoelectrochemical Hydrogen Evolution from Water over Cu₂Sn_xGe_1–xS₃ Particles

Abstract

Cu2Sn x Ge1–x S3 (CTGS) particles were synthesized via a solid-state reaction and assessed, for the first time, as both photocatalysts and photocathode materials for hydrogen evolution from water. Variations in the crystal and electronic structure with the Sn/Ge ratio were examined experimentally and theoretically. The incorporation of Ge was found to negatively shift the conduction band minimum, such that the bandgap energy could be tuned over the range 0.77–1.49 eV, and also increased the driving force for the photoexcited electrons involved in hydrogen evolution. The effects of the Sn/Ge ratio and of Cu deficiency on the photoelectrochemical performance of Cu2Sn x Ge1–x S3 and Cu y Sn0.38Ge0.62S3 (1.86 < y < 2.1) based photocathodes were evaluated under simulated sunlight. Both variations in the band-edge position and the presence of a secondary impurity phase affected the performance, such that a particulate Cu1.9Sn0.38Ge0.62S3 photocathode was the highest performing specimen. This cathode gave a half-cell solar-to-hydrogen energy conversion efficiency of 0.56% at 0.18 V vs a reversible hydrogen electrode (RHE) and an incident-photon-to-current conversion efficiency of 18% in response to 550 nm monochromatic light at 0 VRHE. More importantly, these CTGS particles also demonstrated significant photocatalytic activity during hydrogen evolution and were responsive to radiation up to 1500 nm, representing infrared light. The chemical stability, lack of toxicity, and high activity during hydrogen evolution of the present CTGS particles suggest that they may be potential alternatives to visible/infrared light responsive Cu–chalcogenide photocatalysts and photocathode materials such as Cu­(In,Ga)­(S,Se)2 and Cu2ZnSnS4.

NiPS3 ultrathin nanosheets as versatile platform advancing highly active photocatalytic H2 production

“…The Raman spectrum of NiPS 3 UNSs (Supplementary Fig. 8a) exhibits the presence of E (2) g , A (1) 1g , A (2) 1g and A (3) 1g modes, in agreement with the prior report 60 . Moreover, the UV-Vis absorption spectrum of NiPS 3 UNSs (Supplementary Fig.…”

Interfacial chemical bond and internal electric field modulated Z-scheme Sv-ZnIn2S4/MoSe2 photocatalyst for efficient hydrogen evolution

“…In the past few years, metal chalcogenide semiconductor photocatalyst, such as ZnS, CdS, PbS, ZnIn 2 S 4 , have absorbed extensively attention due to the favorable visible-light response ability [6][7][8] . ZnIn 2 S 4 is a typical ternary layered metal chalcogenide semiconductor with adjustable band gap of 2.06~2.85 eV, besides, the conduction band is about −1.21 eV, suggesting the intense reducing capacity of the photogenerated electrons 9 .…”

Limbic Inducted and Delocalized Effects of Diazole in Carbon Nitride Skeleton for Propelling Photocatalytic Hydrogen Evolution

“…As a promising alternative energy carrier, hydrogen has provoked widespread concern owing to the high energy density and zero environmental footprints upon combustion. − Solar-powered photocatalytic hydrogen evolution (PHE) from splitting of water is expected to realize the assembly of energy-saving and eco-friendly hydrogen production system without complex technology in the future. − Heretofore, the exploitation of high-efficiency semiconductor photocatalysts with a prospect of practical application has always been a challenging issue.…”