The development of water splitting technology is severely impeded by the limited strategies for preparing efficient photocatalyst with optimal structure. Herein, a facile structure and doping engineering strategy is proposed to obtain the atomic-thin mesoporous graphite carbon nitride (g-C₃N₄) nanosheets with a large specific surface area of 212.5 m² g⁻¹, an ultra-large pore volume of 1.55 cm³ g⁻¹, high C and O contents of ∼51.4 and 4.8% via an acid-assisted exfoliation route without any hard templates. The theoretical calculation reveals that the introduction of additional C/O atoms into g-C₃N₄ matrix would boost the charge transfer rate and charge separation efficiency due to the enhanced electronic polarization effect (Bader Charge) and shortened bond lengths. Additionally, the electronic conductivity is demonstrated to be enhanced due to the formation of delocalized π-bonding both experimentally and theoretically. The synergic contribution of textural and electronic features renders an excellent photoelectrochemical (PEC) performance with 50–60 times larger photocurrent in comparison with the pristine g-C₃N₄ and high hydrogen evolution rates of 830.1 and 115.5 μmol g⁻¹ h⁻¹ under the solar- and visible-light irradiation, respectively. This in-situ exfoliation approach demonstrates a facile yet efficient method to synthesize highly porous carbon nitride materials with optimal structure and composition for efficient water splitting.

制备具有最佳结构的高效光催化剂的策略有限，严重阻碍了水分解技术的发展。本文提出了一种简便的结构和掺杂工程策略，以获得比表面积为212.5 m ²  g ^-1，超大孔体积为1.55的原子薄介孔石墨碳氮化物（gC ₃ N ₄）纳米片。 cm ³  g ^-1，在没有任何硬模板的情况下，通过酸辅助剥离途径，其C和O含量较高，分别约为51.4和4.8％。理论计算表明，将额外的C / O原子引入gC ₃ N ₄由于增强的电子极化效应（Bader Charge）和较短的键长，基体将提高电荷转移速率和电荷分离效率。另外，由于在实验上和理论上都形成了离域的π键，因此证明了电导率得到了提高。与原始gC ₃ N ₄相比，结构特征和电子特征的协同作用提供了出色的光电化学（PEC）性能，光电流大50-60倍，并且氢的高析出速率为830.1和115.5μmolg ^-1  h ^-1分别在太阳光和可见光照射下。这种原位剥落方法证明了一种简便而有效的方法，可以合成具有最佳结构和成分的高孔隙度氮化碳材料，以进行有效的水分解。