聚合物半导体g-C3N4因较窄带隙、稳定性高、成本低等特点而在污染物降解和清洁能源生产方面引起了广泛关注。但纯g-C3N4光催化剂电荷分离率低、电荷重组率高等缺点导致其光催化能力不理想，因此改善g-C3N4的光催化性能是目前光催化领域的研究热点。通过构造异质结、元素掺杂等改性手段制备的g-C3N4基光催化剂增强了对可见光的吸收，光催化能力强，拥有较好的工业应用前景。本工作首先简单介绍了g-C3N4基光催化剂的研究现状，其次概述了其制备方法的研究现状并介绍了几种制备g-C3N4工艺及特点，说明了应用不同制备工艺时应注意的问题。此外对其光催化性能提升途径的机理进行阐述，并且指明了发展方向，最后进行总结和展望。在后续研究中，若能有效结合材料科学与环境科学的优势，开发结构稳定和光催化性能优异的g-C3N4基光催化复合材料对提高其实际价值具有重要意义。

The polymer semiconductor g-C3N4 has attracted widespread attention in fields such as pollutant degradation and clean energy production due to its features such as narrow band gap, high stability, low cost, etc. However, there are some drawbacks of g-C3N4 that it has low charge separation rate, high charge recombination rate, etc., which lead to its unsatisfactory photocatalytic ability. Therefore, improving the photocatalytic performance of g-C3N4 has become a research hotspot in the field of photocatalysis. The g-C3N4-based photocatalysts prepared by heterojunction construction, elemental doping and other modification methods can enhance the absorption of visible light and have strong photocatalytic ability, which have wide industrial application prospects. In this work, firstly, the research actuality of g-C3N4-based photocatalysts was briefly introduced. Secondly, this work discussed the research status of preparation methods and introduced several preparation methods for g-C3N4. It also explained the problems that should be paid attention to when applying different preparation processes. In addition, various mechanisms of the approaches to improve its photocatalytic performance were illustrated, and the development directions were pointed out, summarized and prospected. In the follow-up research, if the advantages of material science and environmental science can be effectively combined to prepare g-C3N4-based photocatalyst composites with stable structure and excellent photocatalytic performance, it will be of great significance to improve practical value of g-C3N4.