In this study, a bimetallic Pt-Ni alloy catalyst, designated PN 0.5 /VCN 1 , was synthesized with the objective of enhancing the photocatalytic hydrogen evolution performance. Photoelectrochemical characterizations confirm that PN 0.5 /VCN 1 significantly improves light absorption, charge transfer efficiency, and proton adsorption/activation capability, leading to enhanced photocatalytic performance. The results demonstrate that under optimized conditions (300 W Xe lamp, lactic acid as the hole scavenger) PN 0.5 /VCN 1 achieves a hydrogen evolution rate of 8.77 mmol·g -1 ·h -1 (4079 times higher than pure CN) with remarkable stability. And stability tests over four cycles (20 h total) indicate no significant activity loss. This enhancement is attributed to the localized surface plasmon resonance (LSPR) effect of the alloy, interfacial electron redistribution, and synergistic metal-defect interactions. The modification strategy proposed in this study offers a rational and cost-effective approach for efficient photogenerated charge separation and accelerated proton reduction kinetics, providing a competitive advantage in the market. This work provides a foundation for designing high-performance photocatalytic systems.
Developing and designing highly active and robust catalysts for the methanol oxidation reaction (MOR) are imperative towards the commercialization of direct methanol fuel cells. Herein, a Pt–Ni alloy catalyst (Pt1.5Ni-NGA) with ultrafine size (2.68 nm) and surface defects was designed and fabricated via a facile acid-leaching reconstruction strategy. The microstructural analysis showed that abundant surface defects were created in the Pt1.5Ni-NGA catalyst and are considered highly active methanol oxidation catalytic sites. Consequently, Pt1.5Ni-NGA exhibited a remarkable performance for MOR, achieving 6.3-times higher mass activity (MA, 1.88 A mg−1) in comparison with the commercial Pt/C catalyst (0.30 A mg−1). Simultaneously, Pt1.5Ni-NGA retained 79.8% of its initial MA after 10 000 s durability measurement in the acidic medium, demonstrating its improved durability. The experimental results revealed that the surface defects and modified electronic structure contributed to the enhanced MOR performance of Pt1.5Ni-NGA. This work offers a novel perspective for the rational construction of efficient Pt-based nanomaterials with defects for methanol oxidation.
Efficient and low-cost nanocatalysts are extremely desirable for the catalytic reduction of 4-nitrophenol (4-NP). A smaller nanocatalyst particle size and stronger support effect can significantly enhance the catalytic performance. Naturally occurring halloysite nanotubes (HNTs) are promising alternative supports for fine metal nanoparticles, but the smooth surface and single type of functional groups on HNTs are usually unfavorable for the anchoring of metal ions. Herein, we modified HNTs using a mild and controllable molten salt etching method to create a rough surface (rHNTs), followed by loading Pt–Ni alloys to prepare Pt–Ni/rHNTs for the catalytic reduction of 4-NP. The results demonstrate that ultrafine Pt–Ni alloy nanoparticles with a diameter of 1.60 nm are uniformly dispersed on the rough surface of rHNTs. The particle size and catalytic performance can be tuned by adjusting the loading amount of Pt–Ni. The optimized Pt–Ni/rHNT (1 wt %) nanocatalyst reveals the smallest Pt–Ni particle size and the highest catalytic rate of 0.1953 min−1, which exceeds many Pt–Ni-based catalysts in previous reports. This work offers an ingenious idea for the mild surface modification of HNTs and a brilliant perspective for the rational design of inexpensive 4-NP reduction nanocatalysts.
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