Search

Co-catalysts for H 2 production are often made from expensive noble metals, such as the most efficient Pt. The alternative non-noble metal co-catalysts with low cost and high efficiency are therefore highly desirable for economically viable H 2 production. Herein, we demonstrated that a CdS/MoS 2 /Mo sheets system simultaneously containing photocatalysts, co-catalysts, and conductive supports, was prepared via the one-step hydrothermal process by Mo sheets as template and Mo sources. The obtained CdS/MoS 2 /Mo sheets possess the superior photocatalytic H 2 production via water splitting under visible light irradiation, which achieved an extraordinary H 2 production of 4540 μmol h −1 g −1 , up to 28.6 and 3.6 times greater than that of CdS alone and Pt/CdS. The synergetic effect of MoS 2 as co-catalysts and Mo sheets as conductive supports contribute to the dramatically improved photocatalytic H 2 evolution activity of CdS photocatalysts, by means of facilitating charge carriers separation and providing active sites for proton reduction. These findings provide a straightforward and practical route to produce cheap and efficient co-catalysts for large-scale water splitting. [ABSTRACT FROM AUTHOR]

Electrochemical water splitting is crucial for sustainable energy, enabling hydrogen fuel conversion, storage, and energy transfer. This review focuses on innovative approaches to replace costly precious metal catalysts with earth-abundant elements, known for their high catalytic activity and durability in alkaline hydrogen evolution reactions. Designing self-supporting electrodes, particularly using three-dimensional (3D) nickel foam (NF) substrates, has emerged as an effective strategy to enhance electrocatalyst performance and stability. The continuous porous structure of 3D NF ensures excellent electrical conductivity and a larger active surface area. This review extensively catalogs emerging nanostructured materials directly grown on 3D NF, including sulfides, phosphides, layered double hydroxides, nitrides, oxides, selenides, and alloys. Emphasis is placed on their cutting-edge achievements in structural design, controllable synthesis, performance optimization, and elucidation of catalytic mechanism. These insights facilitate the selection and fabrication of high-performance self-supporting electrodes, accelerating the commercialization and scalability of water electrolysis technology. [Display omitted] • Outlined the fundamental advancements in nickel foam-based electrocatalysts for hydrogen evolution in water splitting. • Elucidated the enhanced hydrogen evolution performance through the utilization of 3D nickel foam. • Provided future directions and insights into self-supporting 3D nickel foam-based electrocatalysts for hydrogen evolution. [ABSTRACT FROM AUTHOR]

• Metallic Ni 3 Mo 3 N porous microrods showed a low overpotential of 44.6 mV to attain a current density of 10 mA cm−2 and superstability at a large current density of 1100 mA cm−2 for 50 h. • Density functional theory (DFT) calculations clarified that the Ni 3 Mo 3 N electrocatalyst possesses various HER catalytic active sites with suitable ΔG H* values (more than ten sites) due to the metallic semiconductor structure with special electronic structure. • The constructed NC/Ni 3 Mo 3 N/NF||NiMoO 4 ·xH 2 O/NF only needed a voltage of 1.58 V to attain a current density of 50 mA cm−2, which was better than that of 20 wt% Pt/C||RuO 2 (1.71 V), and has high potential for large-scale industrial applications. The low onset potential and large current density of electrocatalysts has always been important target for hydrogen evolution reaction (HER). In especial, the large current density (larger than 1000 mA cm−2) is an important criterion for the evaluation of electrocatalysts for industrial application. Usually, the number of catalytic sites in electrocatalyst limits the current density for HER. To overcome these problems, bimetallic nitride is controllably synthesized, and the corresponding catalytic sites are regulated by a bimetallic effect. Herein, an inexpensive electrocatalyst consisting of N-doped carbon-coated porous Ni 3 Mo 3 N microrods (NC/Ni 3 Mo 3 N/NF) is cultured on nickel foam using a hydrothermal reaction and subsequent nitriding process. The designed electrocatalyst consisting of porous NC/Ni 3 Mo 3 N microrods displays efficient catalytic activity for hydrogen evolution reaction (HER), with a small overpotential of 136 mV to achieve a cathodic current density of 100 mA cm−2. Density functional theory (DFT) calculations clarified that the Ni 3 Mo 3 N electrocatalyst possesses various HER catalytic active sites with suitable ΔG H* values (more than ten sites) due to the metallic semiconductor structure with special electronic structure. It is important that NC/Ni 3 Mo 3 N/NF possess perfect superstability for HER, with a large current density of 1100 mA cm−2 for 50 h. Lastly, NC/Ni 3 Mo 3 N/NF and NiMoO 4 ·xH 2 O/NF are hired as the cathode and anode, respectively, to assemble the two-electrode electrolytic cell, thereby achieving excellent overall water splitting performance with a voltage of 1.58 V at 50 mA cm−2 in 1 M KOH aqueous solution. [ABSTRACT FROM AUTHOR]

• Saccharomycetes are used as green phosphorus source to produce metal phosphides. • Interface phosphating for solid-solid contact can efficiently utilize phosphorus. • Graphitizing & migration of metal-catalyzed carbon matrix to form hollow structure. • The Ni/Ni 3 P heterostructure can weaken strong Ni–H bonding to obtain small Δ G H*. • Achieve hydrogen production from wastewater treatment at low input voltages. The development of new, clean and efficient catalytic materials for hydrogen evolution reaction (HER) has become extremely unstoppable. Herein, the heterostructural Ni-Ni 3 P nanoparticles embedded into N\P co-doped carbon shells on 3D graphene frameworks (Ni-Ni 3 P@NPC/rGO) was synthesized via an in situ phosphatization of nickel well-integrated with the structure engineering of carbon matrix derived from saccharomycetes. The in-situ phosphating process of nickel using P source provided by saccharomycetes is particularly simple, economical and environmentally friendly. In addition, the as-prepared Ni-Ni 3 P@NPC/rGO exhibits superior bifunctional electrocatalytic performance toward both HER (extremely low overpotential of 113 mV at 20 mA cm–2) and urea degradation reaction (UDR, only 1.38 V to attain 50 mA cm–2). Furthermore, a two-electrode electrolyzer employing the 3D block electrode (Ni-Ni 3 P@NPC/rGO/GFB) couple on both cathode and anode, can produce higher current density with lower voltage in urea-based wastewater splitting less than pure water splitting (saved 448 mV to deliver 500 mA g–1). [ABSTRACT FROM AUTHOR]