Activation of peroxymonosulfate via g-C3N4/CeO2 heterojunction for efficient degradation of nitenpyram under visible light

Photocatalytic cooperation with peroxymonosulfate (PMS) is considered to be an advanced oxidation process for purifying wastewater. This research synthesized g-C3N4/CeO2 (GC) heterojunction catalysts and achieved efficient PMS activation under visible light. This catalyst has a reasonable band structure and efficient charge transfer ability. The experimental results indicated that within 60 min, the degradation efficiency of nitenpyram (NTP) by the GC/PMS/Vis system could reach 85.5 % (pH = 6.68), and the reaction rate constant was 1.74 times and 1.96 times that of the g-C3N4/PMS/Vis and CeO2/PMS/Vis systems, respectively. Additionally, this research systematically demonstrated that the GC belongs to type-II heterojunction, and employed electron spin resonance (ESR) and quenching experiments to ascertain that the system is dominated by singlet oxygen (O-1(2)), hole (h(+)), and superoxide (center dot O-2(-)). In the natural organic matter experiments and cyclic experiments, the system demonstrated excellent stability and anti-interference ability, with the degradation efficiency remaining above 80 %. These results furnish a novel perspective for the rational configuration of transition metal oxide/PMS/Vis systems and concurrently disclose new revelations regarding the degradation of neonicotinoid pesticides.