Hollow structured photocatalysts

Abstract

Photocatalysis technology, utilizing solar-driven reactions, is poised to emerge as a reliable strategy to alleviate environmental and energy pressures. Thus, whether the photocatalytic performance is excellent depends on the reasonable design of photocatalysts. By considering factors such as morphology engineering, band gap engineering, co-catalyst modification, and heterojunction construction, the photocatalysts with superior performance can be developed. Inspired by this unique characteristic, photocatalysts with a hollow structure endow numerous advantages in photocatalyst design, including enhanced multiple refraction and reflection of light, reduced transport distance of photo-induced carriers, and provided plentiful surface reaction sites. Herein, we systematically review the latest progress of hollow structured photocatalysts and summarize the diversity from geometric morphology, internal structure, and chemical composition. Specifically, the synthetic strategies of hollow structured photocatalysts are highlighted, including hard template, soft template, and template free methods. Furthermore, a series of hollow structured photocatalysts have also been described in detail, such as metal oxide, metal sulfide, metal-organic framework, and covalent organic framework. Subsequently, we present the potential applications of hollow structured photocatalysts in photocatalytic pollutant degradation, H₂ production, H₂O₂ production, CO₂ reduction, and N₂ fixation. Simultaneously, the relevant relationship between hollow structure and photocatalytic performance is deeply discussed. Toward the end of the review, we introduce the challenges and prospects in the future development direction of hollow structured photocatalysts. The review can provide inspiration for better designing hollow structured photocatalysts to meet the needs of environmental remediation and energy conversion.