Characterizations of high nitrogen-doped rice straw biogas residue biochars and their photocatalytic antifouling activity

Marine fouling caused major economic losses and has been a global challenge on environment protection. Currently, photocatalytic played an important role in dealing with sea pollution, enhancing the ability of resisting the bacteria and algae effectively. Rice straw biogas residue biochar with the natural in-situ nitrogen functional group has been widely utilized in the field of photocatalytic. The nitrogen functional group could effectively improve the photogenerated carrier transport rate. In addition, Cu₂O as a typical photocatalyst could boost the photocatalytic ability, improving the performance of photocatalytic antifouling. In this work, the rice straw biogas residue biochar and Cu₂O composited material (BRC) was synthesized by hydrothermal treatment and utilized in the field of photocatalytic and pollution removal. The natural nitrogen-containing lignocellulosic biochar was carbonized from rice straw biogas residue after anaerobic digestion and hydrothermal treatments. The BRC could impede the electron-hole complexation and continuously and efficiently generate reactive oxygen species (ROS), possessing an efficient photo-utilization rate. The BRC could exhibit excellent photocatalytic antifouling performance, with an antimicrobial rate of more than 95 %, and Chlorella adhesion density reduced by 94 %. In addition, BRC not only realized the resourceful utilization of agricultural waste, but also had a good prospect for the practical application of marine antifouling.