Highly efficient hydrogen production using p-Si wire arrays and NiMoZn heterojunction photocathodes

[Display omitted] •Vertically aligned ca. 4μm-long p-Si microwire arrays are fabricated via a quick etching process within 5min.•NiMoZn particles are photoelectrochemically deposited onto the Si wires for 5min.•The p-Si wire array/NiMoZn produces Iph of ∼1.45mAcm−2 at 0V vs. RHE with a ∼100% Faradaic efficiency for H2 evolution.•This Iph value is ∼10-fold greater than that with the planar Si/NiMoZn samples.•The excellent performance of the p-Si wire arrays/NiMoZn heterojunctions is discussed. Highly efficient photoelectrochemical (PEC) hydrogen production is achieved using p-Si wire arrays loaded with NiMoZn particles in aqueous sulfuric acid under simulated sunlight (AM 1.5G; 100mWcm−2). Vertically-aligned wire arrays are grown on planar Si wafers via a quick electroless etching process within 5min, leading to short Si wires of ∼4 μm and diameters of ∼0.2μm. Despite the short length of the wires, the reflectance of the arrays is