Tailoring GaN nanorods with MoS2 on tungsten foil for enhanced photoelectrochemical performance

Researchers from CSIR- National Physical Laboratory and Indian Institute of Technology Madras have developed an innovative heterostructure of MoS₂-decorated GaN nanorods on tungsten foil, promising a significant advancement in photoelectrochemical (PEC) water splitting technology, as detailed in their recent publication in Frontiers in Energy.

Gallium nitride (GaN) nanostructures are renowned for their excellent electron mobility, chemical stability, and large surface area, making them ideal candidates for PEC water splitting. However, their wide bandgap (~3.4 eV) limits solar absorption, hindering performance. To overcome this, researchers sought to enhance GaN's efficiency by integrating it with molybdenum disulfide (MoS₂), a material known for its superior catalytic properties.

The study unveiled that MoS₂/GaN nanorods exhibited an impressive photocurrent density of approximately 172 µA/cm², nearly 2.5 times the performance of bare GaN nanorods, which showed only ~70 µA/cm². This enhancement is attributed to the Type II band alignment between MoS₂ and GaN, facilitating efficient charge separation, reduced charge transfer resistance, and increased active sites.

The research team employed a combination of atmospheric pressure chemical vapor deposition (CVD) and laser molecular beam epitaxy (LMBE) to fabricate the MoS₂/GaN heterostructures on tungsten foil. The hexagonal phases of both materials were confirmed through Raman spectroscopy and X-ray diffraction, while X-ray photoelectron spectroscopy was used to examine their electronic states.

This breakthrough offers a promising strategy to increase PEC efficiency in solar water splitting applications. The successful integration of MoS₂ with GaN nanorods not only enhances performance but also opens new avenues for developing more efficient solar-driven hydrogen production systems. This could significantly contribute to sustainable energy solutions and reduce reliance on fossil fuels.

The research was funded by the CSIR-FIRST (MLP211732) and SAMMARTH (HCP-55). The detailed findings can be accessed in the full paper published in Frontiers in Energy: https://journal.hep.com.cn/fie/EN/10.1007/s11708-025-1035-z. Future research will focus on further optimizing the heterostructure and exploring its scalability for industrial applications.