A Novel Charge Transfer Channel to Simultaneously Enhance Photocatalytic Water Splitting Activity and Stability of CdS

Abstract

It is highly desirable to develop durable photocatalysts for efficiently boosting water splitting, but it is challenging for CdS to realize the expected result without using any hole sacrificial agents. Herein, improved photocatalytic hydrogen evolution and enhanced stability are simultaneously realized in the absence of any sacrificial agents by introducing Zinc 5-, 10-, 15-, 20-mesotetra (4-hydrazidephenyl) porphyrin (ZnTHPP) onto CdS nanosheets (CdS NSs). In this system (ZnTHPP/CdS NSs), a novel hole transfer channel is achieved by an internal chemical reaction using the functional group of acylhydrazine in ZnTHPP. Compared with CdS NSs, the ZnTHPP/CdS NSs exhibit excellent photostability (15 h) and efficient photocatalytic activity for pure water splitting (≈6.4 times). Furthermore, it is found that the rate constant for photogenerated holes is about 1.7 times higher than the pure CdS NSs under light irradiation. This suggests that the promising charge transfer channel can efficiently suppress charge recombination and photocorrosion of pure CdS NSs. The pattern via internal charge transfer channel not only can solve the stability of CdS based materials, but also design more semiconductors for efficient photocatalytic water splitting.

Cross‐Linked Surface Engineering to Improve Iron Porphyrin Catalytic Activity

“…Recently, metal‐complex with specific catalytic activity have been immobilized on various carrier surfaces to construct organic/inorganic interfaces by surface molecular engineering to form a solid catalytic center with a clear chemical structure and function, thereby converting a homogeneous catalytic reaction into a heterogeneous catalytic reaction, improving catalytic efficiency, and solving the problem of catalysts recovery. [ 23–27 ] Taking account of advantages and unique properties of metal‐porphyrins such as excellent electron donors with delocalized π systems, rigid and planar geometry, high thermal stability, high electron stability, small band, adjustable band gap, excellent optical, and ideal redox behavior, [ 28–31 ] a type of tetrakis(4‐carboxyphenyl)‐porphyrin‐Fe (TCPP‐Fe) based QTD ultra‐thin metallized film materials was constructed by in‐situ deposition of TCPP‐Fe molecule chelated with iron ions (Fe(III)) on the surface of hollow nanocages by cross‐linked surface engineering. Our aim is to improve the catalytic performance of HZIF@TCPP‐Fe/Fe catalyst on oxidative dehydrogenation of aromatic hydrazides and investigate the basic mechanism.…”

Research Frontiers in Energy‐Related Materials and Applications for 2020–2030

“…[137] However, in practice, materials with a bandgap of at least 1.6 eV are preferred to compensate for energy losses. [140,141] Since the pioneering works by Fujishima and Honda on TiO 2 in the 70s, many metal oxides have been studied for their photocatalytic activity (Fe 2 O 3 , ZnO, WO 3 , CoO, BiVO 4 , etc.). [140,141] Since the pioneering works by Fujishima and Honda on TiO 2 in the 70s, many metal oxides have been studied for their photocatalytic activity (Fe 2 O 3 , ZnO, WO 3 , CoO, BiVO 4 , etc.).…”

“…[138,139] Besides the bandgap, another critical parameter is the stability and durability of the materials toward chemical and photochemical degradation. [141] Metal sulfides, like CdS and ZnS, possess a smaller bandgap (for example, the bandgap of CdS is 2.25 eV, which allows absorption of solar radiation in the visible region) but are much less stable toward photocorrosion than metal oxides. These inorganic materials exhibit high stability in general but tend to have relatively large bandgaps, which limit the harvest of solar energy to a portion of the UV region.…”

“…However, in practice, materials with a bandgap of at least 1.6 eV are preferred to compensate for energy losses . Besides the bandgap, another critical parameter is the stability and durability of the materials toward chemical and photochemical degradation . Since the pioneering works by Fujishima and Honda on TiO 2 in the 70s, many metal oxides have been studied for their photocatalytic activity (Fe 2 O 3 , ZnO, WO 3 , CoO, BiVO 4 , etc.).…”

“…Since the pioneering works by Fujishima and Honda on TiO 2 in the 70s, many metal oxides have been studied for their photocatalytic activity (Fe 2 O 3 , ZnO, WO 3 , CoO, BiVO 4 , etc.). These inorganic materials exhibit high stability in general but tend to have relatively large bandgaps, which limit the harvest of solar energy to a portion of the UV region . Metal sulfides, like CdS and ZnS, possess a smaller bandgap (for example, the bandgap of CdS is 2.25 eV, which allows absorption of solar radiation in the visible region) but are much less stable toward photocorrosion than metal oxides .…”