Robust non-Pt noble metal-based nanomaterials for electrocatalytic hydrogen generation

Currently, the electrocatalytic hydrogen evolution reaction (HER) has been a key point of focus for developing sustainable hydrogen economy, but it is hampered by sluggish reaction kinetics. Despite the fact that various non-noble metal-based materials as electrocatalysts toward the HER are gaining considerable attention, noble metal-based nanomaterials (NMNs) for catalyzing the HER still have advantageous features, i.e., wide pH applicability, high intrinsic activity, and good stability. Considering a high chemical similarity to HER-benchmark Pt metals, various non-Pt NMNs with high atom utilization, super efficiency, and durability for HER catalysis are engineered through various structural/electronic tailoring strategies, which has become a significant trend in this research field. Herein, a panoramic review about recent representative efforts and progress in the design of non-Pt NMNs is presented. It first introduces the HER fundamentals and then generally describes the structural and electronic characteristics of non-Pt noble metals matching the HER. Followed on, different tuning strategies for fabricating effective non-Pt NMN catalysts, including composition optimizing by constructing alloys or novel compounds, morphological tuning via decreasing the particle size or designing unique nanostructures, and hybrid engineering as well as crystalline structure/facet controlling, are systemically summarized, with a special focus on the underlying structure-activity relationship for different catalysts. The features of pH universality and bifunctionality for these non-Pt NMN catalysts are also highlighted. At the end, existing challenges and future perspectives awaiting this emerging research field are discussed.