Engineering GaN-based systems for photocatalysis: strategies and applications.

Photocatalytic technology plays an irreplaceable core role in energy conversion, environmental remediation, and chemical synthesis by enhancing reaction rates and selectivity, thereby advancing clean energy technologies and green chemistry. Among various photocatalytic materials, GaN has garnered significant attention owing to its unique physical and chemical properties. GaN features a hexagonal wurtzite crystal structure and a direct bandgap, alongside excellent chemical and thermal stability. Compared to traditional semiconductor materials, GaN exhibits superior corrosion resistance, more efficient photogenerated charge carrier separation, and broader application potential. In recent years, the application of GaN in photocatalysis has expanded continuously, covering fields such as water splitting for hydrogen production, CO2 photoreduction to fuels, fixation of N2, degradation of organic pollutants, and conversion of small organic molecules. This review highlights how, by integrating strategies such as nanostructure design, elemental doping, heterostructure construction, and surface defect engineering, GaN-based catalytic systems have achieved significant improvements in the light absorption range, carrier dynamics, and catalytic stability. Systematic studies and continuous optimization of GaN photocatalytic performance will provide essential support and innovative impetus for the advancement of efficient energy conversion and environmental remediation technologies.