Ammonia, the second most-produced chemical, is widely used in agricultural and industrial applications. However, traditional industrial ammonia production dominated by the Haber–Bosch process presents huge resource and environment issues due to the massive energy consumption and CO₂ emission. The newly emerged nitrogen fixation technology, photocatalytic N₂ reduction reaction (p-NRR), uses clean solar energy with zero-emission, holding great prospect to achieve sustainable ammonia synthesis. Although great efforts are made, the p-NRR catalysts still suffer from poor N₂ adsorption and activation, inferior light absorption, and fast recombination of photocarriers. Due to the tunable electronic structure of the metal-free polymeric graphitic carbon nitride (g-C₃N₄), the above-mentioned issues can be significantly alleviated, making it the most promising p-NRR photocatalyst. This review summarizes the recent development of g-C₃N₄-based catalysts for p-NRR, including the working principle of p-NRR catalysts, the challenges of developing p-NRR catalysts, and corresponding solutions. Particularly, the roles of defect engineering and heterojunction construction on g-C₃N₄ to the enhancement of photocatalytic performances are emphasized. In addition, computational studies are introduced to deepen the understanding of reaction pathways. At last, perspectives are provided on the development of p-NRR catalysts.

中文翻译：

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石墨氮化碳基催化剂在光催化固氮中的应用研究进展

氨是产量第二大的化学品，广泛用于农业和工业应用。然而，以Haber-Bosch工艺为主导的传统工业氨生产由于大量的能源消耗和CO ₂排放，存在巨大的资源和环境问题。新兴的固氮技术光催化N ₂还原反应（p-NRR）利用清洁的太阳能零排放，实现可持续合成氨的前景广阔。尽管做出了很大努力，但p-NRR催化剂仍然存在N ₂吸附和活化差、光吸收差、光载流子复合快等问题。由于无金属聚合物石墨氮化碳（gC₃ N ₄ )，上述问题可以得到显着缓解，使其成为最有前途的p-NRR光催化剂。本综述总结了gC ₃ N ₄基p-NRR催化剂的最新进展，包括p-NRR催化剂的工作原理、开发p-NRR催化剂面临的挑战以及相应的解决方案。_{特别强调了gC 3} N ₄上的缺陷工程和异质结构建对提高光催化性能的作用。此外，还引入了计算研究以加深对反应途径的理解。最后，展望了p-NRR催化剂的发展。