Activation Strategy of WS₂ as an Efficient Photocatalytic Hydrogen Evolution Cocatalyst through Co²⁺ Doping to Adjust the Highly Exposed Active (100) Facet

Abstract

As an effective method to improve the surface catalytic activity of catalysts, crystal plane engineering has become a research hot spot in recent years. Doping regulation of the highly exposed facet with low surface energy is helpful to expand their applications in the field of photocatalysis. Therefore, low concentration transition metal ions (Co2+) in the high exposure surface (100) of WS2 by one‐pot hydrothermal method are doped. Moreover, density functional theory (DFT) calculation shows that after Co2+ in WS2 (100) crystal replaces W4+, the surface charge is rearranged, and the local charge near Co2+ is enhanced, which accelerates the electron transfer rate, makes the electron transfer rapidly to (100) facet through the secondary transfer process, and finally promotes proton reduction. Therefore, the hydrogen production efficiency of 7% (Co–WS2)/Cd0.4Zn0.6S (CZS) Schottky junction (21 000 μmol g−1 h−1) is 9.3 times and 1.3 times higher than that of CZS (2265 μmol g−1 h−1) and 7% WS2/CZS heterojunction (17 000 μmol g−1 h−1). This study has certain reference and guiding significance for the study of new cocatalysts, not only on pristine semiconductor but also for semiconductor‐based hybrid structures.

Surface‐Activated Ti3C2TxMXene Cocatalyst Assembled with CdZnS‐Formed 0D/2D CdZnS/Ti3C2‐A40Schottky Heterojunction for Enhanced Photocatalytic Hydrogen Evolution

“…In contrast, CZS NPs were prepared by the microwave‐assisted solvothermal method in our previous study. [ 21 ] Finally, CZS NPs could homogeneously grow onto the surfaces of Ti 3 C 2 ‐A x to produce a 0D/2D Schottky junctions through electrostatic assembly under ultrasonic conditions. Furthermore, the prepared CZS/Ti 3 C 2 ‐A 40 hybrids have a suitable negative zeta potential (−4.38 mV) (Table S1, Supporting Information), which will facilitate the adsorption of free protons and desorption of H 2 after the reduction reaction.…”

Increasing unsaturated Se number and facilitating atomic hydrogen adsorption of WSe2+x nanodots for improving photocatalytic H2 production of TiO2

“…19,20 Thus, the active-site number and efficiency of cocatalysts should be maximized as much as possible to signicantly improve the H 2evolution performance. However, most of the cocatalysts, especially non-noble metals (such as NiS x , Mo 2 C, and CoP x ), 14,21,22 generally exhibit low active-site number and efficiency due to their unfavourable structural conguration and electronic properties, [23][24][25] which seriously limit the improvement of H 2 -evolution performance. Therefore, it is quite pivotal to optimize the microstructure of cocatalysts for simultaneously increasing their active-site number and efficiency so as to achieve efficient photocatalytic H 2 -evolution activity.…”

Hollow ZnCdS and NiCoP Nanostructures for Photocatalytic Hydrogen Generation

“…19−21 Unfortunately, many cocatalysts seriously limit H 2 -production efficiency at the active sites due to their undesired binding energy to H ads . 22,23 However, metal phosphides (MPs), especially transition-metal phosphides (TMPs), acting as single photocatalysts, have shown highefficiency photocatalytic hydrogen evolution activities in a dye sensitization system. 24 Moreover, because of their inherent semimetallic nature, high electrical conductivity, and phys- icochemical stability, TMPs as cocatalysts also exhibit electron transport performance comparable to or even beyond that of noble metals such as Pt.…”

“…The introduction of cocatalysts has been proved to be an efficient way to construct high-efficiency photocatalysts because they can not only promote the rapid migration of electrons but also effectively capture and activate H + ions (or H 2 O molecules) on the photocatalyst surface. , Meanwhile, cocatalysts as active sites can also greatly reduce the energy barrier of H 2 generation. − Unfortunately, many cocatalysts seriously limit H 2 -production efficiency at the active sites due to their undesired binding energy to H ads . , However, metal phosphides (MPs), especially transition-metal phosphides (TMPs), acting as single photocatalysts, have shown high-efficiency photocatalytic hydrogen evolution activities in a dye sensitization system . Moreover, because of their inherent semimetallic nature, high electrical conductivity, and physicochemical stability, TMPs as cocatalysts also exhibit electron transport performance comparable to or even beyond that of noble metals such as Pt.…”