Synthesis and characterization of spent coffee grounds derived activated carbon-supported ZnO for photocatalyst

Abstract Spent coffee grounds derived activated carbon-supported ZnO as photocatalyst has been synthesized. This study analyzes the characteristics of adding activated carbon from spent coffee grounds to ZnO as a candidate photocatalyst material. The stages in this research are preparing activated carbon from spent coffee grounds, synthesis of ZnO/activated carbon, and characterization of ZnO/activated carbon. Based on the activated carbon quality test results, 13% ash content and 6.6% ash content were obtained, which met the standards. ZnO/activated carbon characteristics showed that all samples of activated carbon addition of 0.4 g, 0.9 g, and 1.4 g showed the dominant crystalline phase of ZnO. Adding 1.4 g activated carbon to ZnO gives suitable characteristics as a photocatalyst, resulting in a particle size of 45.22 nm and a band gap energy of 3.20 eV.