Novel marigold-like CuO@Cu-based MOFs composite photocatalyst for high-performance removal of alkylphenol ethoxylate under visible light

Abstract

Alkylphenol polyethoxylate (APEOn) is an emerging contaminant mainly referred to nonylphenol polyethoxylate (NPEOn) and octylphenol polyethoxylate (OPEOn). A novel multiscale rough composite photocatalyst (CuO@Cu-H3BTC) with marigold-flower nanosheets and sub-micron flakes was successfully constructed for photodegradation of OPEOn and NPEOn under visible light. Several technologies (such as SEM, EDS, FTIR, XRD, XPS and EPR) were utilized to characterize the structures and properties of the as-obtained sample. The effect of OPEOn and NPEOn removal by CuO@Cu-H3BTC MOF and the influence of reaction conditions on the removal efficiency were explored. It was found that 96% of OPEOn and 79% of NPEOn were removed under the action of adsorption in darkness and degradation in visible light irradiation within 120 min when treating 25 mg/L OPEOn and NPEOn solution with 1.6 g/L of CuO@Cu-H3BTC MOF composite. The corresponding OPEOn and NPEOn removal efficiency could still achieve almost 72% and 51% after the CuO@Cu-H3BTC MOF was recycled five times, respectively. The degradation mechanism of APEOn investigation revealed that the free radicals and holes generated in the CuO@Cu-H3BTC MOF degraded APEOn, and the existence of holes was confirmed to play the major role through quenching experiment. In summary, this facile and novel CuO@Cu-H3BTC MOFs composite photocatalyst boosts the application platform in wastewater treatment.