Photochemical and electrochemical assessment of UIO-66-NH₂/g-C₃N₄ thin-film heterostructures as potential candidates for hydrogen evolution: an experimental study augmented by DFT insights

Interfacial engineering regulated by CeO to boost efficiently alkaline overall water splitting and acidic hydrogen evolution reaction

This paper introduces HER activity of a string of Ni–P nanoparticles. The hydrogen evolution reaction (HER) activity of different Ni–P nanoparticles hinges on elemental ratios of nickel to phosphorus and nickel phosphide phases through annealing processes, which lead to utter diverse HER performances in H2SO4 and NaOH. The sample annealed under 350 °C by 4 h, mainly comprised by Ni3P and Ni12P5, shows overpotential of 333 mV to achieve 100 mA·cm−2 (η100 = 333 mV) current density in acidic condition, whereas in alkaline condition, the non-heat-treated sample, mainly formed by Ni12P5 and Ni2P, shows the best HER performance. Ni–P nanoparticles have also displayed distinguished durability in both H2SO4 and NaOH. The superior HER activity and durability are supported by a series of characterizations and stem from Ni–P nanoparticles’ nature, including their morphology, good ensemble effect between nickel and phosphorus, and anti-corrosive quality.

Ex situ flame vapor-doped oxophilic metals on WP/WOx nanowires for enhanced alkaline hydrogen evolution activity

Efficient hydrogen evolution performance of phase-pure NiS electrocatalysts grown on fluorine-doped tin oxide-coated glass by facile chemical bath deposition

Constructing heterostructure of CeO2/WS2 to enhance catalytic activity and stability toward hydrogen generation

Transition metal and phosphorus co-doping induced lattice strain in mesoporous Rh-based nanospheres for pH-universal hydrogen evolution electrocatalysis

Ru nanoparticles supported on partially reduced TiO2 as highly efficient catalyst for hydrogen evolution

Thin Films Fabricated by Pulsed Laser Deposition for Electrocatalysis

Plasma-regulated two-dimensional high entropy oxide arrays for synergistic hydrogen evolution: From theoretical prediction to electrocatalytic applications

Anion-Modulated Platinum for High-Performance Multifunctional Electrocatalysis toward HER, HOR, and ORR.

Constructing superhydrophilic CoRu-LDH/PANI nanowires with optimized electronic structure for hydrogen evolution reaction

With increasing global demand for energy, rapid depletion of fossil fuels and intensification of environmental concerns, exploring clean and sustainable energy carriers to replace fossil fuel is becoming critical. Among the various alternatives, hydrogen has been intensively regarded as a promising energy carrier to fulfill the increasing energy demand due to its large energy density per unit mass and eco-friendly production possibilities. However, hydrogen does not exist in molecular structure in nature, and it is essential to obtain efficient and sustainable H2 production technologies. Alkaline water electrolysis is an effective, clean and sustainable process to produce high-quality hydrogen. In this process, highly active electrocatalysts for the hydrogen evolution reaction (HER) are required to accelerate the sluggish kinetics and lower the overpotentials (η) for efficient hydrogen evolution. To date, a noble metal, platinum (Pt), is the state-of-art electrocatalyst for HER. However, exploration of alternative electrocatalysts with low cost and excellent electrocatalytic activity is of vital importance to realize large-scale hydrogen production through water electrolysis. Generally, an electrochemically active catalyst should have an optimal hydrogen adsorption free energy to allow efficient catalytic hydrogen adsorption/desorption. In alkaline solution, dissociation of water onto the electrocatalyst determines the overall HER efficiency. This thesis focuses on rational design and synthesis of different earth-abundant electrocatalysts for electrocatalytic HER in alkaline media. Through facile anion or cation doping strategies, electrocatalysts with abundant accessible active sites, enhanced electronic conductivity and accelerated HER kinetics have been systematically fabricated, characterized and evaluated. First, an efficient HER electrocatalyst in alkaline media was fabricated by incorporating sulfur atoms into a cobalt (hydro)oxide crystal structure. The resultant catalyst exhibits a remarkably enhanced HER activity with a low-overpotential of 119 mV at 10 mA/cm2 and an excellent durability. The results suggest that cobalt hydroxide benefits water adsorption and cleavage, while the negatively charged sulfur ligands facilitate hydrogen adsorption and desorption on the surface of electrocatalysts, leading to significantly promoted Volmer and Heyrovsky steps for HER in alkaline media. Second, exploring bifunctional electrocatalysts which can simultaneously accelerate the HER and oxygen evolution reaction (OER) activities plays a key role in alkaline water splitting. Here, sulfur atoms were incorporated into the mixed transition metal hydroxide with high OER performance to render excellent HER activity. The enhanced catalytic activity towards HER was confirmed by a synergistic effect between the retained metal hydroxide host and the incorporated sulfur atoms. In addition, the full water splitting electrolyzer equipped with fabricated bifunctional electrocatalysts as anode and cathode materials exhibited remarkable overall water splitting performance comparable to that with benchmark Pt and RuO2 electrocatalysts. The S/Se co-doped Co3O4 nanosheets on carbon cloth were fabricated by a facile room temperature chalcogen atom incorporation methodology and were applied as the electrocatalyst for HER in alkaline media. The sulfur and selenium atoms were homogeneously distributed on the surface by forming Co-S or Co-Se bonds which play a key role in the structural change in electrochemical activation. The obtained electrocatalysts demonstrated remarkably improved HER activity compared to that of the original Co3O4. Finally, molybdenum doped cobalt hydroxide was fabricated with significantly accelerated HER kinetics. The introduced Mo sites not only effectively facilitate water dissociation process and desorption of the OHads intermediates, but also simultaneously optimize the hydrogen adsorption free energy. Therefore, the in situ-generated Mo-doped amorphous cobalt hydroxide exhibited a remarkable HER performance in alkaline media with an overpotential of only -80 mV at a current density of 10 mA/cm2. This thesis innovatively explores strategies to improve the catalytic activity towards HER of metal (hydro)oxide in alkaline media. The surface foreign atom doping was demonstrated to manipulate the surface structure of catalysts, thus not only improving the water dissociation processes, but also facilitating the hydrogen adsorption/desorption on the catalysts. The demonstrated facile and effective strategies could be adopted for the fabrication of cost-effective and highly active catalysts for other important chemical reactions for energy conversion applications.

Rational construction of hierarchical porous FeP nanorod arrays encapsulated in polypyrrole for efficient and durable hydrogen evolution reaction

Fabrication of 3D-interconnected microporous carbon decorated with microspheres for highly efficient hydrogen evolution reactions

Facile synthesis of interlaced flower-like layered double hydroxides grown on porous CoMoP as a highly efficient electrocatalyst for hydrogen evolution reaction