Review on Photogenerated Hole Modulation Strategies in Photoelectrocatalysis for Solar Fuel Production

Abstract

PEC) technique provides a clean, lowcost, and environmental-friendly route with great potential for addressing energy crisis mainly through water splitting and CO 2 reduction by utilizing solar energy. In general, it is favorable for the added external electric field to greatly modulate the photogenerated electrons in PEC process. However, it is a ratedetermining step as another half-reaction for the photogenerated hole to induce water oxidation since it is usually involved with 4 electrons for O 2 evolution. Thus, it is highly desired to develop feasible strategies to modulate photogenerated hole for efficient solar-to-energy conversion. Unfortunately, it is frequently neglected compared to the electron regulation. Obviously, it is much meaningful to develop new efficient strategies for photogenerated hole modulation, along with to review recent developments. Herein, this minireview summarizes the recent developments of photoexcited hole modulation for PEC process to nanosized semiconductors, and it is highlighted for the strategies successfully developed in our group in recent years, mainly including surface polarization by modifying inorganic acids and halogen anions, and non-metallic element doping. Moreover, related conclusions and several outlooks are put forward.[a] Dr.

Semiconductor Electrode Materials Applied in Photoelectrocatalytic Wastewater Treatment—an Overview

“…During the photocatalytic processes, the semiconductor is irradiated by light photons with the energy being equal to or higher than its band gap energy. If the photocatalytic process is combined with the electrochemical degradation, photogenerated e − /h + pairs are separated by the bias potential supplied to the semiconductor [22,51,[75][76][77]. Additionally, combination of photocatalytic and electrochemical techniques results in an increase in wastewater treatment due to the generation of highly reactive hydroxyl radicals (OH • ).…”

An Overview of Solar-Driven Photoelectrochemical CO2 Conversion to Chemical Fuels

“…The half-oxidative reaction not only provides active protons and photoelectrons for cathode but also restricts the reduction reaction rate . Some hole modulation methods have been widely developed to increase the PEC performances, such as surface polarization, transition-metal oxide co-catalyst loading and nonmetallic element doping. − …”

Insights and Progress on Photocatalytic and Photoelectrocatalytic Reactor Configurations and Materials for CO2 Reduction to Solar Fuels

“…On the other hand, photocatalyst materials also demand careful consideration regarding the type of material and chemical properties in the conceptualization of improved photocatalyst efficiency in light absorption. Sun et al reviewed recent developments of photoexcited hole modulation in the PEC process to nanosized semiconductors for solar fuel production, including surface polarization by modifying inorganic acids and halogen anions and nonmetallic element doping. Brito et al also systematically discussed the advances and contributions of functional catalyst materials in PEC CO 2 reduction to hydrocarbon fuels.…”