Phosphorus Dual‐Doped MoO 2 Nanosheet/Multiwalled Carbon Nanotube Hybrid as Efficient Electrocatalyst for Hydrogen Evolution

Encapsulating N‑doped graphite carbon in MoO2 as a novel cocatalyst for boosting photocatalytic hydrogen evolution

Generally, it is important to ameliorate the co-catalyst used in photocatalytic hydrogen evolution reactions (PHERs) to achieve efficient transfer and separation of photogenerated carriers, decrease the surface reaction energy barrier, and hence improve the photocatalytic activity. In this study, N-doped graphite carbon (GC) was introduced in situ to MoO₂ to ensure the presence of well-dispersed active sites, lower the overpotential of hydrogen evolution, and further achieve high conductivity. Then, the MoO₂/GC composite obtained was used as a co-catalyst of ZnIn₂S₄ (ZIS) in a PHER, resulting in a great improvement in the photocatalytic activity. Given the metallicity and large work function of MoO₂/GC, a Schottky interface can form between MoO₂/GC and ZIS, which accelerates the transmission of photogenerated electrons. As a result, the separation efficiency of photogenerated carriers improves, whereas the surface overpotential of PHERs clearly decreases for ZIS. This study proposes a new idea for exploiting efficient co-catalysts and promotes the wide and heavy use of carbon materials in the field of solar energy conversion.

One-step coating of Ni–Fe alloy outerwear on 1–3-dimensional nanomaterials by a novel technology

A simple one-step electrodeposition approach was developed to manufacture Ni–Fe alloy@1–3-dimensional core–shell nanomaterials using a novel technology.

Chemically Robust, Cu-based Porous Coordination Polymer Nanosheets for Efficient Hydrogen Evolution: Experimental and Theoretical Studies

Due to the extremely high number of accessible active sites and short diffusion path, porous coordination polymer (PCP) nanosheets have demonstrated a variety of promising applications, especially for energy conversion and mass transfer. However, the development of chemically stable PCP nanosheets with dense active sites and large lateral size is a great challenge in terms of feasible considerations. Herein, we first designed and prepared a kind of chemically stable PCP nanosheets via a bottom-up and a top-down integral strategy. Featuring densely exposed and periodic Cu²⁺ active sites (2.1 × 10⁶ per μm²), as well as ultrathin nature (5 nm) and significant pores (18 Å), this nanosheet demonstrated remarkable performance of electrocatalytic hydrogen evolution. Furthermore, one plausible process and the effect of Cu²⁺ active sites were proposed and validated by density functional theory calculations.

Nano-Cu-Mediated Multi-Site Approach to Ultrafine MoO2 Nanoparticles on Poly(diallyldimethylammonium chloride)-Decorated Reduced Graphene Oxide for Hydrogen Evolution Electrocatalysis

Catalysts with high atom utilization efficiency accompanied by improved reactivity and durability are highly desired. Metallic MoO₂ with its small size easily agglomerates, making it difficult to use in water splitting to obtain hydrogen by electrolysis. Here, the nano-Cu-mediated multi-site method is proposed to prepare ultrafine MoO₂ nanoparticles (NPs) dispersed on poly(diallyldimethylammonium chloride)-decorated reduced graphene oxide (denoted as MoO₂ /PDDA-rGO). The introduction of Cu NPs increases the number of growth sites for MoO₂ on the PDDA-rGO and simultaneously promotes the growth rate of MoO₂ on PDDA-rGO. As a consequence, the resulting size of the MoO₂ NPs is only 2 nm and these are evenly dispersed on PDDA-rGO. Significantly, the optimized catalyst has a low onset potential of -42 mV versus reversible hydrogen electrode (RHE), a calculated Tafel slope of only 42 mV dec^-1 , and good cycling stability of more than 40 h. This favored hydrogen evolution reaction (HER) activity is caused by the synergistic effects of MoO₂ and PDDA-rGO, rapid charge transport, and sufficient exposed active sites of MoO₂ /PDDA-rGO.

Facile synthesis of Cu2MoS4 nanosheet/multi-walled carbon nanotube composites as a high-efficiency electrocatalyst for hydrogen evolution

A Cu₂MoS₄/MWCNT electrocatalyst with enhanced HER performance was synthesized for the first time, in which Cu₂MoS₄ nanosheets are intimately interlinked by MWCNTs.