Design of ordered Ag/AgBr nanostructures coupled activated carbon with enhanced charge carriers separation efficiency for photodegradation of tetracycline under visible light

Abstract

Oriented design of ordered Ag/AgBr photocatalyst with high separation of photoinduced charge carriers is crucial for high catalytic performance. In this work, ordered Ag/AgBr nanostructures were synthesized by a facile thermal polyol method in the presence of char-microwave assisted activated carbon (AABR-ACK). The influence of four synthesis key variables comprising of the mass of surfactant, the temperature, the mass of catalyst support and time, and their simultaneous interactions on the photodegradation of tetracycline (TC) were investigated using response surface methodology (RSM). The time and temperature had significant influence on the TC photocatalytic removal under visible light, as observed from the RSM model. The analysis of XRD, FTIR, SEM, optical and electrochemical properties for AABR-ACK composites evidenced the formation of ordered nanostructures with enhanced charge carriers separation efficiency. It was found that 92% of TC was decomposed after 180 min by optimized AABR-ACK 11. Furthermore, the inorganic phosphate anion retards the degradation performance of AABR-ACK 11 on TC removal. The AABR-ACK 11 composite also exhibits higher activity and reusability for degradation of TC without any major reduction in the performance. This work provides new insight into engineering ordered Ag/AgBr nanostructures through optimization of synthesis variables, with potential application for degradation of antibiotic pollutants.