Graphitic carbon nitride (g-CN) has attracted great interest in photocatalytic water splitting. However, the poor photogenerated charge carriers transfer and the insufficient driving force for oxygen evolution reaction limit its practical application. In this work, boron-doped g-CN nanosheets (BCNS) have been synthesized by calcining a mixture of g-CN and NaBH. The synthesized BCNS were then combined with TiC MXene using electrostatic self-assembly to construct a 2D/2D BCNS/TiC heterojunction. The resultant BCNS retained the original framework of g-CN, while the optimized band structure of BCNS induced prominently enhanced visible light absorption, accelerated charge carriers separation, and the increased driving force for water oxidation compared to pure g-CN Density functional theory further proved that BCNS can enhance the driving force for photocatalytic O evolution. Moreover, the construction of 2D/2D face-to-face BCNS/TiC heterojunction was carried out to further enhance photocatalytic performance due to the intimate contact interface and the accelerated separation and transfer of photogenerated charge carriers. As a result, the 2D/2D BCNS/TiC hetrojunction exhibited a dramatically improved photocatalytic water-splitting performance compared to pristine g-CN. This integrated engineering strategy, involving non-metal element doping and 2D/2D heterojunction construction, might provide a unique paradigm for the rational design of efficient photocatalysts for photocatalytic water splitting.

中文翻译：

---

用硼掺杂 g-C3N4 和 Ti3C2 MXene 构建 2D/2D BCNS/Ti3C2 异质结以增强光催化水分解

石墨氮化碳（g-CN）在光催化水分解方面引起了人们的极大兴趣。然而，光生载流子传输不良和析氧反应驱动力不足限制了其实际应用。在这项工作中，通过煅烧 g-CN 和 NaBH 的混合物合成了硼掺杂的 g-CN 纳米片 (BCNS)。然后利用静电自组装将合成的 BCNS 与 TiC MXene 结合，构建 2D/2D BCNS/TiC 异质结。所得的BCNS保留了g-CN的原始骨架，而优化的BCNS能带结构与纯g-CN相比，显着增强了可见光吸收，加速了载流子分离，并增加了水氧化的驱动力。密度泛函理论进一步证明BCNS可以增强光催化析氧的驱动力。此外，由于紧密的接触界面和光生电荷载流子的加速分离和转移，进行了2D/2D面对面BCNS/TiC异质结的构建，以进一步增强光催化性能。因此，与原始 g-CN 相比，2D/2D BCNS/TiC 异质结表现出显着改善的光催化水分解性能。这种涉及非金属元素掺杂和2D/2D异质结构建的集成工程策略可能为合理设计用于光催化水分解的高效光催化剂提供独特的范例。