The existence of chromium in hexavalent oxidation state is highly toxic to aquatic environment. Photocatalytic reduction of hexavalent Cr (VI) into Cr (III) has emerged as a desirable technology due to their prospect in solar energy utilization, high efficiency and low cost. Graphitic carbon nitride (g-C₃N₄)-based photocatalysts are ideal for Cr (VI) reduction due to their inherent features including; visible-light responsive narrow bandgap, suitable conduction band potential, high physicochemical stability, unique optical and electronic properties. Herein, various surface-interface strategies to modify g-C₃N₄ including heterojunction formation, doping, structural regulation, co-catalyst loading and construction of nitrogen vacancies are elaborated for improving the Cr(VI) photoreduction efficiency. The review also highlights the effect of operational reaction conditions such solution pH, g-C₃N₄ dosage, Cr (VI) concentration, temperature, light source, organic acid additives and co-existing ions influencing Cr (VI) reduction efficiency. Finally, we attempt to propose the existing issues based on the current research and future aspects of engineered g-C₃N₄ for Cr (VI) photoreduction.

六价氧化态铬的存在对水生环境有剧毒。由于其在太阳能利用、高效和低成本方面的前景，光催化将六价 Cr (VI) 还原为 Cr (III) 已成为一种理想的技术。石墨氮化碳 (gC ₃ N ₄ ) 基光催化剂由于其固有特性，是还原 Cr (VI) 的理想选择：可见光响应窄带隙，合适的导带电位，高物理化学稳定性，独特的光学和电子特性。在这里，各种表面界面策略来修改 gC ₃ N ₄包括异质结形成、掺杂、结构调节、助催化剂负载和氮空位的构建，以提高 Cr(VI) 光还原效率。该评论还强调了操作反应条件的影响，例如溶液 pH 值、gC ₃ N ₄用量、Cr (VI) 浓度、温度、光源、有机酸添加剂和共存离子对 Cr (VI) 还原效率的影响。最后，我们尝试根据工程化 gC ₃ N ₄用于 Cr (VI) 光还原的当前研究和未来方面提出现有问题。