Piezocatalytic Effect Induced Hydrogen Production from Water over Non-noble Metal Ni Deposited Ultralong GaN Nanowires

Piezoelectric material-based catalysis that relies on an external stress-induced piezopotential has been demonstrated to be an effective strategy toward various chemical reactions. In this work, non-noble metal Ni-decorated ultralong monocrystal GaN nanowires (NWs) were prepared through a chemical vapor deposition (CVD) technique, followed by a photodeposition method. The piezocatalytic activity of the GaN NWs was enhanced by similar to 9 times after depositing the Ni cocatalyst, generating hydrogen gas of similar to 88.3 mu mol.g(-1).h(-1) under ultrasonic vibration (110 W and 40 kHz), which is comparable to that of Pt-loaded GaN NWs. Moreover, Ni/GaN NWs with smaller diameters (similar to 100 nm) demonstrated superior piezocatalytic efficiency, which can be attributed to the large piezoelectric potential evidenced by both finite-element analysis and piezoresponse force microscopy measurements. These results demonstrate the promising application potential of non-noble metal loaded GaN nanostructures in hydrogen generation driven by weak mechanical energy from the surrounding environment.

Automated summary

Piezoelectric catalysis using Ni-decorated GaN nanowires has been shown to enhance hydrogen generation by 9 times compared to Pt-loaded GaN nanowires under ultrasonic vibration, with superior efficiency observed in Ni/GaN nanowires with smaller diameters. The results demonstrate the potential application of non-noble metal loaded GaN nanostructures in hydrogen generation driven by weak mechanical energy.