Photocatalytic H2 evolution with a Cu2WS4 catalyst on a metal free D-Π-A organic dye-sensitized TiO2

A system comprising of a noble metal free Cu2WS4 catalyst and donor-π-bridge-acceptor metal-free organic dyes (MZ-341 and MZ-235) sensitized TiO2 has been reported for the photocatalytic hydrogen production using triethanolamine (TEOA) as the sacrificial reagent under visible light irradiation. Cu2WS4 nanocubes were synthesized according to hot-injection reaction technique. The structural properties of the Cu2WS4 nanocubes were examined by microscopy (HR-TEM) and XRD techniques where the formation of nanocubes (rectangular and square cubes) with average edge length to be ranged from 100 to 500 nm and tetragonal phase (I-42m) was proved respectively. It was found that MZ-341 and MZ-235 dyes sensitized TiO2 have been produced 661 μmol g−1 h−1 and 531 μmol g−1 h−1 hydrogen, respectively in TEOA solution at pH 9. When Cu2WS4, was used as a co-catalyst, hydrogen evolution by MZ-341 and MZ-235 sensitized TiO2 have been slightly increased to 1406 μmol g−1 h−1 and 943 μmol g−1 h−1, respectively.