Water EPD based of 2D-Bi2WO6 ultrathin film on innovative designed substrates: Efficient photocatalytic degradation of binary antibiotics

Abstract

In this work, a new nanoflake morphology for Bi2WO6 ultra–thin film was successfully coated from an aqueous electrolyte by the electrophoretic deposition method. Two SS mesh sheets were interlaced as an innovative designed substrate. The new structures of double substrates played vital role in the light harvesting because of more available catalyst surfaces and great influence in photocatalytic issues. These films were applied for photocatalytic degradation of metronidazole and amoxicillin in binary and single modes as pharmaceutical pollutant models. The observed results confirmed the remarkable photocatalytic degradation activity due to the innovative designed substrates made the new film morphology having higher light harvesting sites. Two cross interlaced sheets (double form) provided more available light trapping and harvesting surfaces due to small vacancy sites between two substrates which prevented from the light crossing comparison with the simple mesh sheet (single form). Electrochemical impedance spectroscopy and photocurrent studies suggested the higher separation of photogenerated hole/electrons for the double mode of substrates. It can be assigned to the low film thickness resulted in the short charge transfer route and enhanced photocatalytic efficiency. Catalyst surface has the low adsorption ability within the large molecules of amoxicillin; in the single mode pollutant solution; led to the low catalytic efficiency. But in the binary mixture, higher catalytic ability for amoxicillin degradation was observed. In addition, new nanoflakes retarded the charge recombination by creation of new routes made the more desired photocatalytic degradation. On can conclude, this innovative designed substrate will open the new arena filed for construction of the photocatalytic tools applicable in the large scale up of environmental pollutants.