Innovative Catalyst Design of Sea-Urchin-like NiCoP Nanoneedle Arrays Supported on N-Doped Carbon Nanospheres for Enhanced HER Performance.

Hydrogen (H2) stands as a clean energy alternative to fossil fuels, especially within the domain of the hydrogen evolution reaction (HER), offering prospective solutions to mitigate both environmental and energy-related challenges. In this work, we successfully synthesized a sea-urchin-like catalyst, specifically a nickel-cobalt phosphide nanoneedle array on N-doped carbon nanospheres (Ni0.5Co1.5P@NCSs), for efficient HER by a sequential hydrothermal and low-temperature phosphating process. The catalyst exhibits sea-urchin-like structures, offering a specific surface area of 298 m2 g-1 and consequently furnishing a greater abundance of active sites. Comparing with non-sea-urchin-like Ni0.5Co1.5P@CN catalysts, the Ni0.5Co1.5P@NCSs exhibit an overpotential of 163 mV at 10 mA cm-2, a Tafel slope of 60 mV dec-1, and a maintained current density of approximately 90% during 50 h of continuous electrolysis. Experiments demonstrate that the outstanding electrochemical properties of the Ni0.5Co1.5P@NCSs originate from nitrogen doping of carbon spheres, the distinctive morphology of sea-urchin-like nanoneedle arrays, and simultaneous enhancements in intermediate adsorption energy, charge transfer, and electrolyte diffusion channel shortening. This work emphasizes a preparation strategy for synthesizing an attractive electrocatalyst with a low cost and efficient HER performance.

Efficient metal-organic framework-based dual co-catalysts system assist CdS for hydrogen production from photolysis of water.

Metal-organic framework materials (MOFs) and their derivatives have been widely used in the field of photocatalytic water decomposition for hydrogen production. In this study, NiS/CdS was initially acquired and subsequently combined with DUT-67 via ultrasound to create a unique ternary photocatalyst NiS/CdS@DUT-67. The rate of hydrogen production for NiS/CdS@DUT-67 is 9618 µmol·g NiS/CdS-1·h-1 for NiS/CdS@DUT-67, which is 32 times and 2.5 times higher than that for CdS and NiS/CdS, respectively. Of particular interest is the fact that even after 50 h of photocatalysis, the hydrogen production rate did not show a significant decrease, demonstrating its excellent stability compared to CdS and NiS/CdS. In this ternary system, NiS and DUT-67 function as dual co-catalysts for CdS, collaborating to enhance charge separation during the photocatalysis. This study presents a clear demonstration of the advantages of utilizing metal-organic framework derivatives (MOF-derivatives) cophotocatalysts and their synergistic effect, resulting in improved photocatalytic activity and stability of semiconductors. This innovative approach provides a new perspective on constructing photocatalytic materials with exceptional performance.