TiO 2 Nanorods Co‐decorated with Metal‐Free Carbon Materials for Boosted Photoelectrochemical Water Oxidation

Semiconducting Polymers for Oxygen Evolution Reaction under Light Illumination

Sunlight-driven water splitting to produce hydrogen fuel has stimulated intensive scientific interest, as this technology has the potential to revolutionize fossil fuel-based energy systems in modern society. The oxygen evolution reaction (OER) determines the performance of overall water splitting owing to its sluggish kinetics with multielectron transfer processing. Polymeric photocatalysts have recently been developed for the OER, and substantial progress has been realized in this emerging research field. In this Review, the focus is on the photocatalytic technologies and materials of polymeric photocatalysts for the OER. Two practical systems, namely, particle suspension systems and film-based photoelectrochemical systems, form two main sections. The concept is reviewed in terms of thermodynamics and kinetics, and polymeric photocatalysts are discussed based on three key characteristics, namely, light absorption, charge separation and transfer, and surface oxidation reactions. A satisfactory OER performance by polymeric photocatalysts will eventually offer a platform to achieve overall water splitting and other advanced applications in a cost-effective, sustainable, and renewable manner using solar energy.

Assembling γ-graphyne surrounding TiO2 nanotube arrays: an efficient p-n heterojunction for boosting photoelectrochemical water splitting

Photoelectrochemical water splitting is an excellent strategy for hydrogen generation and it is pivotal to the development of photoanodes with sufficient sunlight harvesting, rapid charge separation, and enhanced electron injection efficiency. In this work, we rationally constructed a γ-graphyne/TiO₂ (GY/TiO₂) p-n heterojunction in which p-type γ-graphyne nanosheets were distributed in the three-dimensional space surrounding TiO₂ nanotube arrays. The GY/TiO₂ photoanode achieves a photocurrent density of 0.75 mA cm^-2 at 1.23 V (vs. RHE), 1.7 times that of bare TiO₂, and extends the electron lifetime of TiO₂ from 0.51 to 1.16 ms. The improvement arises from moderate γ-graphyne modification, contributing to broadened light absorption, the suppressed recombination of electron-hole pairs, an increase in charge transfer, and a higher injection efficiency of surface electrons. This work provides a reliable approach for the utilization and conversion of sustainable solar energy.