Charge Steering in Heterojunction Photocatalysis: General Principles, Design, Construction, and Challenges

Abstract

Steering charge kinetics is a key to optimizing quantum efficiency. Advancing the design of photocatalysts (ranging from single semiconductor to multicomponent semiconductor junctions) that promise improved photocatalytic performance for converting solar to chemical energy, entails mastery of increasingly more complicated processes. Indeed, charge kinetics become more complex as both charge generation and charge consumption may occur simultaneously on different components, generally with charges being transferred from one component to another. Capturing detailed charge dynamics information in each heterojunction would provide numerous significant benefits for applications and has been needed for a long time. Here, the steering of charge kinetics by modulating charge energy states in the design of semiconductor–metal‐interface‐based heterogeneous photocatalysts is focused. These phenomena can be delineated by separating heterojunctions into classes exhibiting either Schottky/ohmic or plasmonic effects. General principles for the design and construction of heterojunction photocatalysts, including recent advances in the interfacing of semiconductors with graphene, carbon quantum dots, and graphitic carbon nitride are presented. Their limitations and possible future outlook are brought forward to further instruct the field in designing highly efficient photocatalysts.

Synergetic Electromagnetic Enhancement and Charger Transfer in Boat-Like Au/PbS/Au Nanohybrids with Increased SERS Activity for Ultrasensitive Molecular Detection

“…The PbS, Au/PbS, and boat-like Au/PbS/Au hybrids were used as the photoanode coatings. As shown in Figure a, the Au/PbS has much higher photocurrent density than PbS, which can be understood as the plasmon-enhanced charge generation and transfer from metal to semiconductor. − Noticeably, the boat-like Au/PbS/Au hybrids have higher photocurrent density than Au/PbS, indicating that the further growth of the Au shell on Au/PbS can improve the charge generation and transfer. The photocurrent density of boat-like Au/PbS/Au hybrids is highly dependent on the size of the surface nanocavity.…”

Twinned crystal Cd0.9Zn0.1S/MoO3 nanorod S-scheme heterojunctions as promising photocatalysts for efficient hydrogen evolution

“…To solve these issues, researchers have obviously improved the catalytic activity of the semiconductors through many methods such as element doping, 11 morphology control, 12 defect engineering, 13,14 and building heterojunctions. 15,16 Among these approaches, the construction of type II heterojunctions, 17 Z-scheme heterojunctions, 18 and S-scheme heterojunctions 19,20 has become a focal point. Type II heterojunctions enable the separation of photogenerated electrons and holes, facilitating effective spatial charge transfer.…”

Fluorinated Metal–Organic Frameworks with Dual-Functionalized Linkers to Enhance Photocatalytic H2 Evolution and High Water Adsorption

“…Hydrogen evolution from water can be an effective strategy to deal with the energy crisis in the current conditions, where the shortage of energy and environmental pollution have challenged the world. , The replacement of nonrenewable energies with clean hydrogen energy can potentially address the challenges faced globally. , Scientists have examined different procedures for H 2 production, including the development of various semiconductor-based photocatalysts like oxides, sulfides, oxynitrides, and nanocomposites, since Fujishima and Honda discovered TiO 2 photocatalysts. , Yet, the commercial applications of metal oxides are mainly limited considering the flash recombination of photoexcited electron–hole pairs . Advanced photocatalysts are currently based on materials with a shorter synthesis pathway and less energy consumption.…”

“…5,6 Yet, the commercial applications of metal oxides are mainly limited considering the flash recombination of photoexcited electron− hole pairs. 7 Advanced photocatalysts are currently based on materials with a shorter synthesis pathway and less energy consumption. The application of nonprecious metals with considerable stability and a high ability to absorb light and water molecules can lead to the ideal performance of a photocatalytic process.…”