Hydrogen Evolution Performances of Different Z-Scheme Configurations Composed of Ta3N5 and WO3 on a Nanohoneycomb Substrate

In order to improve the hydrogen evolution efficiency of Ta3N5, it was coupled with WO3 to form a Z-scheme with two different configurations to reduce the recombination rate of electrons and holes. Furthermore, a nanohoneycomb (nHC structure was fabricated to serve as the substrate to provide 2 times larger surface area than that of a planar substrate for the water splitting reaction. Both Ta3N5 and WO3 films were deposited on the nHC by atomic layer deposition. The Z-scheme was constructed with two different deposition sequences, Ta3N5/ WO3 (denoted as TNVV0@nHC) and WO3/Ta3N5 (denoted as WOTN@nHC). They generated 1.5 and 3.2 times higher hydrogen evolution rates, respectively, than that of Ta3N5@nHC under 300 W Xe lamp irradiation. With the Pt cocatalyst and under visible light irradiation, the hydrogen evolution rates of 7.8 and 15.6 mu mol/g h, respectively, were obtained, which were also higher than that of Ta3N5@nHC, 5.2 mu mol/g h. The highest rate of the sample Pt@WOTN@nHC was ascribed to the WO3 protection layer, better crystallinity, and electron tunneling.