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Graphitic carbon nitride (g-C3N4)-based photocatalysts have garnered significant interest as a promising photocatalyst for hydrogen generation under visible light, to address energy and environmental challenges owing to their favorable electronic structure, affordability, and stability. In spite of that, issues such as high charge carrier recombination rates and low quantum efficiency impede its broader application. To overcome these limitations, structural and morphological modification of the g-C3N4-based photocatalysts is a novel frontline to improve the photocatalytic performance. Therefore, we briefly summarize the current preparation methods of g-C3N4. Importantly, this review highlights recent advancements in crafting high-performance g-C3N4-based photocatalysts, focusing on strategies like elemental doping, nanostructure design, bandgap engineering, and heterostructure construction. Notably, sophisticated doping techniques have propelled hydrogen production rates to a 104-fold increase. Ingenious nanostructure designs have expanded the surface area by a factor of 26, concurrently extending the fluorescence lifetime of charge carriers by 50%. Moreover, the strategic assembly of heterojunctions has not only elevated charge carrier separation efficiency but also preserved formidable redox properties, culminating in a dramatic hundredfold surge in hydrogen generation performance. This work provides a reliable and brief overview of the controlled modification engineering of g-C3N4-based photocatalyst systems, paving the way for more efficient hydrogen production. [ABSTRACT FROM AUTHOR]

Laser cleaning is an advanced cleaning technology which is widely used in the manufacturing industry. Compared with the common planar laser cleaning process, the laser cleaning process of curved surface is difficult to control the completeness and homogeneity of the cleaning layer, which has a great influence on the surface quality and mechanical properties of the cleaned parts. Therefore, a three-dimensional numerical model of the laser cleaning process of the curved surface considering the coordinate system transformation of the heat source is established in this paper to clean the alumina on the surface of the 5754 aluminum alloy. The temperature distribution characteristics for different tangent slopes of the laser cleaning path and the temperature variation with time for different cleaning paths of the laser cleaning process are analyzed. The results show that the proposed method can provide important guiding significance for the practical laser cleaning process of the curved surface. [ABSTRACT FROM AUTHOR]