A Bipolar CdS/Pd Photocatalytic Membrane for Selective Segregation of Reduction and Oxidation Processes

A photocatalyticallyactive bipolar membrane consisting of a CdSphotocatalyst and Pd electrocatalyst has been constructed to carryout environmentally relevant oxidation and reduction processes. Theion exchange property of a bipolar membrane (BPM) has allowed us toload the CdS photocatalyst on one side and Pd electrocatalyst on theother side. By inserting the photocatalytic BPM-CdS/Pd membrane betweenthe two compartments of an H-cell, we can separate the reduction andoxidation processes. Following visible light excitation of CdS inthe BPM-CdS/Pd membrane, we can induce vectorial electron transferfrom CdS to Pd and to an electron acceptor (4-nitrophenol). The holesgenerated at CdS are scavenged by ethanol or 4-chlorophenol. The photocatalyticreduction rate dependence on the Pd loading in the membrane as wellas its effect on modulating the rates of electron and hole transferprocesses are discussed. The design of a semiconductor and metal loadedmembrane paves the way for improving selectivity and efficiency ofphotocatalytic processes.

Automated summary

The construction of a photocatalytically active bipolar membrane consisting of CdS photocatalyst and Pd electrocatalyst allows for separating reduction and oxidation processes, with potential to improve selectivity and efficiency in photocatalytic processes.