State-of-the-art advances in vacancy defect engineering of graphitic carbon nitride for solar water splitting

Abstract

Developing low-cost, efficient, and stable photocatalysts is one of the most promising methods for large-scale solar water splitting. As a metal-free semiconductor material with suitable band gap, graphitic carbon nitride (g-C3N4) has attracted attention in the field of photocatalysis, which is mainly attributed to its fascinating physicochemical and photoelectronic properties. However, several inherent limitations and shortcomings—involving high recombination rate of photocarriers, insufficient reaction kinetics, and optical absorption—impede the practical applicability of g-C3N4. As an effective strategy, vacancy defect engineering has been widely used for breaking through the current limitations, considering its ability to optimize the electronic structure and surface morphology of g-C3N4 to obtain the desired photocatalytic activity. This review summarizes the recent progress of vacancy defect engineered g-C3N4 for solar water splitting. The fundamentals of solar water splitting with g-C3N4 are discussed first. We then focus on the fabrication strategies and effect of vacancy generated in g-C3N4. The advances of vacancy-modified g-C3N4 photocatalysts toward solar water splitting are discussed next. Finally, the current challenges and future opportunities of vacancy-modified g-C3N4 are summarized. This review aims to provide a theoretical basis and guidance for future research on the design and development of highly efficient defective g-C3N4.

A Comprehensive Review on the Boosted Effects of Anion Vacancies in Photocatalytic Solar Water Splitting: Focus on g-C3N4 with Carbon and Nitrogen Vacancies

“…68 In another review, defectinducing methods were explored by atomic number, including doped elements and functionalization, and with decreased atom amounts, mainly C-or N-atom or dual vacancies. 69 The application of defected g-C 3 N 4 for PC solar water splitting has been reviewed by Li et al 70 Generally, despite these past reviews, it is necessary to take a closer look at the literature, especially the papers recently published in 2023 and 2024, to facilitate researchers in filling in the gaps. Also, none of the published review articles have focused on g-C 3 N 4 with C/N vacancies for PC and PEC water splitting.…”