High photocatalytic activity of spent coffee grounds derived activated carbon-supported Ag/TiO2 catalyst for degradation of organic dyes and antibiotics

Titanium dioxide (TiO 2 ) has been considered as a promising photocatalyst for degrading organic pollutants due to its stability, low energy consumption and non-toxicity. Nevertheless, the aggregation tendency, relatively wide band gap and easy recombination of electron-hole pairs confine the photocatalytic activity and practical applications of TiO 2 nanoparticles . Herein, a novel Ag/TiO 2 /carbon skeleton derived from spent coffee grounds (CSCG) ternary photocatalyst was developed by in-situ growth of TiO 2 and Ag nanoparticles onto 3D activated CSCG via a hydrothermal process and subsequent photodeposition method. The utilization of excellent conductive CSCG as catalytic carrier can not only alleviate the aggregation of TiO 2 nanoparticles, but also suppress the recombination of photogenerated electron hole pairs . Besides, the surface plasmon resonance (SPR) effect of Ag reduces the band gap of the material and widens light-responsive region, thereby endowing Ag/TiO 2 /CSCG photocatalyst with enhanced photocatalytic degradability for organic pollutants. The as-prepared photocatalyst exhibits high degradation effects on dyes and antibiotics, such as degradation rate of 96.2% for methylene blue (MB), methyl orange (MO: 94%), tetracycline (TC: 99%), and norfloxacin (NOF: 96%). In addition, the hybrid photocatalyst displays up to 91% degradation efficiency of MB after four cycles. This work presents an innovative perspective to construct TiO 2 -based hybrid photocatalyst for boosting photocatalytic performance of wastewater treatment and environmental remediation.