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Using low cost and high efficiency non-precious bimetallic phosphosulphide as electrocatalyst for hydrogen evolution reaction (HER) is not only convenient but also environment-friendly for industrial production. Therefore, we propose a simple and efficient method to prepare a series of Cu-doped bimetallic phosphosulphide nanosheet arrays on nickel foam (CuNiS@Ni 2 P/NF). The CuNiS@Ni 2 P/NF exhibits the superior HER performance with appropriate doping amount of Cu. It just needs a potential of 144 mV to obtain the current density of 10 mA cm−2 in 1.0 M KOH, which is smaller than that of CuNiS@Ni 2 P/NF-0.25 (206 mV) and CuNiS@Ni 2 P/NF-0.125 (219 mV). The excellent HER performance of CuNiS@Ni 2 P/NF nanosheet arrays can be ascribed to: (i) the moderate Cu-doped effectively optimized the electronic structure and morphology of the electrocatalyst; (ii) typical nanosheet arrays structures exposing more active sites; (iii) the high immanent activity excited by the multi-component synergy. • Cu-doped bimetallic phosphosulphide nanosheet arrays on Ni foam has been prepared. • The moderate amount of Cu doping could optimize the electronic structure of the product. • The typical structure and multi-component synergy contribute to the enhanced performance. [ABSTRACT FROM AUTHOR]

The non-precious transition metal phosphides (TMPs) as robust and effective hydrogen evolution reaction (HER) catalysts have attracted enormous attention, due to the merits of earth-abundance, low price, desirable stability and high efficiency. However, the conventional preparation process of this kind of catalyst is inconvenient. Herein, we report a facile approach toward the fabrication of nickel phosphide (Ni 2 P) assembled on carbon cloth (CC) via the coupling method of electroless plating and low temperature phosphorization. Then, the crystallinity, morphology and chemical component of fabricated self-supporting Ni 2 P/CC catalyst employed for the HER process were characterized, and the HER property was successively evaluated in three types of electrolytes (i.e., acidic, neutral and alkaline solutions). The as-prepared Ni 2 P/CC catalyst displays a remarkable HER performance, which can be corroborated by the small Tafel slope (b = 50 mV dec−1), high exchange current density (j 0 = 6.6 × 10−2 mA cm−2), acceptable overpotential (119 mV) to attain the current density of 10 mA cm−2, as well as the superb stability (<5% decay after 24 h potentiostatic test) in 0.5 M H 2 SO 4. In addition, it should be noted that the HER process of Ni 2 P/CC catalyst can be competent for the reduction of nitrate from the solution, and an efficiency of 63.2% for this nutrient pollutant is achieved. Image 1 • Ni–P coating deposited on CC can be sufficiently phosphorized to Ni 2 P. • Ni 2 P/CC composite can be easily fabricated via a facile approach. • Ni 2 P/CC composite exhibits an excellent HER property. • The HER process is helpful to remove nitrate from the solution. • Ni 2 P/CC sample is competent for the recommended candidate of HER catalyst. [ABSTRACT FROM AUTHOR]

Here, we report an efficient hydrogen evolution reaction (HER) electrocatalyst (Fe@Fe2P/NCNT) fabricated from the phosphorization of partially oxidized iron nanorod encapsulated in nitrogen doped carbon nanotubes (Fe@Fe2O3/NCNT) synthesized from iron trichloride and melamine, which only requires ∼0 mV and 78.2 mV overpotentials to achieve cathodic current densities of 1 mA cm−2 and 10 mA cm−2 with Tafel slope of 52.2 mV dec−1 in acidic media, which exhibits higher HER electrocatalytic activity compared to Fe/NCNT requiring a overpotential of 118.5 mV to attain 10 mA cm−2 with Tafel slope of 92.3 mV dec−1. Due to the phosphorization process, additional active sites coming from Fe2P boost the electrocatalytic activity of Fe@Fe2P/NCNT resulting in decrement in overpotentials by 40.3 mV and 186 mV for 10 mA cm−2 and 50 mA cm−2 compared to Fe/NCNT electrocatalyst, respectively. Meanwhile, Fe@Fe2P/NCNT exhibits ignorable degradation in HER activity after 6000 potential cycles suggesting that the Fe@Fe2P/NCNT with superior HER activity and stability could potentially replace the benchmark Pt/C (overpotential@10 mA cm−2: 31 mV) as efficient HER electrocatalyst for water splitting. Top performance: Fe@Fe2P nanorods encapsulated in nitrogen doped carbon nanotubes show a superior performance as catalysts for the hydrogen evolution reaction with overpotentials of 0 mV and 78.2 mV to deliver catalytic current densities of 1 mA cm−2 and 10 mA cm−2, respectively. [ABSTRACT FROM AUTHOR]

Hitherto, WP has been used as hydrogen evolution reaction (HER) catalyst. However, its activity and complexity of nanostructure synthesis greatly limit applications in hydrogen production. Therefore, in this work, the coral-like WP nanorod arrays propagated on W foils (C-WP/W) are synthesized through an in situ oxidation and phosphorization route. The obtained 3D C-WP/W catalysis system can directly work as hydrogen evolution reaction (HER) electrode, and exhibits excellent activity and stability in either acid or alkaline media. It only requires a small overpotential of 109 and 133 mV at 10 mA/cm 2 , and 189 and 206 mV at 100 mA/cm 2 in 0.5 M H 2 SO 4 and 1.0 M KOH, respectively, which is the best HER catalyst ever reported among pure tungsten phosphide materials. This study paves the way for integrations of 3D HER electrodes with low-cost, high performance and for efficient applications under complicated conditions. [ABSTRACT FROM AUTHOR]

The metal-organic frameworks (MOFs)/derivates emerged as promising catalysts for hydrogen generation from electrolyzing water, however, further improvements in the activities are still awaited. Herein, bimetallic MOFs and the derivates were developed for catalyzing the oxygen evolution reaction (OER) and hydrogen evolution reaction (HER) by regulating the morphology, and activity of the intermediates. We demonstrated the activity and morphology of the catalysts strongly correlated with the atomic ratio of Ni and Co in bimetallic MOFs. The hierarchical Ni 0.1 Co 0.9 -MOF delivered a relatively low overpotential of 384 mV to afford 100 mA/cm2 for OER, but a high overpotential of 512 mV for HER. While the phosphide Ni 0.1 Co 0.9 P only needed an overpotential of 276 mV to deliver 100 mA/cm2 for HER. And we discussed the roles of bimetallic sites and phosphorous in OER and HER in depth. More importantly the Ni 0.1 Co 0.9 -MOF and Ni 0.1 Co 0.9 P were integrated to drive the overall water splitting, at a current density of 10 mA/cm2, the overpotential value is 500 mV. This work provided insights into the exploration of efficient MOFs/derivates catalysts and shed new light on the novel combination for water electrolysis. [Display omitted] • The hierarchical nanoflower morphology is elaborately fabricated. • The OER activity highly depends on the metallic atomic ratio in NiCo-MOF. • Ni 0.1 Co 0.9 -MOF performs the most superior OER performance. • Boosted HER performance is achieved by phosphorization (Ni 0.1 Co 0.9 P). • Paring Ni 0.1 Co 0.9 -MOF and Ni 0.1 Co 0.9 P generate excellent water electrolysis. [ABSTRACT FROM AUTHOR]

• Stainless steel mess with a three-dimensional network structure substrate to grow NiCoP-CoP electroactive catalyst. • NiCoP@SSM electrocatalyst reveals an excellent performance and stability towards hydrogen evolution reaction. • Synergetic effect between Pδ− with a high affinity towards proton-acceptor, and Coδ+/ Niδ+ as hydride-acceptor. The stainless steel mesh (SSM) has received remarkable attention for hydrogen and oxygen evolution reactions. It was demonstrated that the SSM exhibits admirable performance towards oxygen evolution reaction (OER) electrocatalysis, while its catalytic activity for hydrogen evolution reaction (HER) remains quite low. This obstructs the utilization of SSM-based catalysts for sustainable complete water electrolysis. In this study, a facile hydrothermal route followed by a phosphorization process was adopted to transform commercially available SSM materials into high-performance and stable electrocatalysts for alkaline HER. We report an interconnected NiCoP-CoP sponge-like structure on SSM substrate without polymer binder. Benefiting from the 3D construction with high exposed surface area, close contact between electroactive species and conductive surface, and facilitated infiltration of electrolyte, the as-prepared NiCoP@SSM electrocatalyst brought an improved catalytic activity for HER, required a low overpotential of 138 mV to derive a current density of 10 mAcm−2 in 1.0 M KOH aqueous solution. The high performance of the NiCoP@SSM catalyst has also unveiled fast reaction kinetics (presents a small Tafel slope of 74 mV/dec), a relatively large electrochemical active surface area (ECSA), and small charge transfer resistance. Furthermore, the NiCoP@SSM electrode also presented excellent stability during long-term measurements, making it one of the most encouraging HER electrodes to date. This research study paves the way for the development of HER-active electrocatalysts made from SSMs that are commercially available, low-cost, and highly active. [Display omitted] [ABSTRACT FROM AUTHOR]

[Display omitted] • The CoMoP-rGO/CNT was synthesized by hydrothermal and phosphating. • The three-dimensional rGO/CNTs can improve the conductivity of substrate materials. • The vertical open structure of CoMoP nanosheet arrays facilitates mass transfer. • The CoMoP-rGO/CNT exhibits HER activity and durability in pH-universal. Although great progress has been made in the area of electrocatalysis, the design of earth-rich and efficient electrocatalysts remains a major challenge. It is of great significance to explore non-noble metal-based electrocatalysts with efficient and stable performance for hydrogen evolution reaction (HER) in the relatively wide pH range. Herein, a self-supporting three-dimensional (3D) CoMoP-rGO/CNT catalyst was synthesized to achieve high efficiency of HER in acidic and basic solution. The combination of CNTs and rGO improves the conductivity of the substrate material, while the self-supporting structure avoids the use of the binder to expose the active sites, and the open structure of the vertically arranged CoMoP nanosheet arrays is benefit for the interaction between the electrolyte and the active sites. Thus, the CoMoP-rGO/CNT showed excellent activity and durability for HER with a low overpotential of 66 mV and 86 mV at a current density of −10 mA·cm−2 in acidic (0.5 M H 2 SO 4) and basic (1 M KOH) solution, respectively. The three-dimensional structure of CoMoP-rGO/CNT can enhance electron migration and mass transfer, while Co and Mo also play an important role in regulating surface active sites. This work may open a new way for the design of earth-rich and low-cost nanomaterials for electrocatalysis. [ABSTRACT FROM AUTHOR]

[Display omitted] • The electrocatalytic activity of Ni and Co films for HER is enhanced by electro-phosphorization. • The electro-phosphorization are realized in hypophosphite solution under electric current action. • Ni film has an overpotential of 57 mV at 10 mA·cm−2 after phosphorization. The electrodeposited nickel and cobalt films are directly phosphorized in alkaline hypophosphite solution under the action of electric current. After the electro-phosphorization process, the morphology of nickel and cobalt films change obviously, and phosphorus element can be detected in the phosphorized films according to the EDS and XPS tests. The electrocatalytic performance of nickel and cobalt films for hydrogen evolution reaction are obviously enhanced by the electro-phosphorization treatment. Especially, the phosphorized nickel film has an overpotential of 57 mV at the current density of 10 mA·cm−2. [ABSTRACT FROM AUTHOR]

• Develop new CoP nanocrystals by phosphating the Co 3 O 4 nanocubes precursor. • New type of non-metallic HER catalyst with initial potential of only 87 mV. • Self-assembled CoP nanocrystals with good catalytic performance. • Provide new way for preparing efficient and inexpensive HER electrocatalysts. Electrocatalytic water splitting reactions include hydrogen evolution reaction (HER) and oxygen evolution reaction (OER). It provides an effective method for producing high-purity hydrogen as a sustainable energy source. In order to solve the growing energy shortage and environmental damage, the development and synthesis of efficient and inexpensive hydrogen evolution reaction (HER) electrocatalysts is urgently needed. Traditional reaction catalysts such as Pt/Rh/Ir and their oxides (such as IrO 2 , RuO 2) have limited their wide application as electrocatalysts due to their high prices and small reserves. In this work, CoP nanocrystals by phosphating the Co 3 O 4 nanocubes precursor were successfully synthesized. CoP nanocrystals are a new type of non-metallic HER catalyst that can work under alkaline conditions. Its initial potential is only 87 mV at a current density of 10 mA cm−2, and the Tafel slope is 105 mV dec−1. The catalyst can maintain the catalytic performance for 12 h in 1 M KOH solution, and the performance can still be maintained above 95.44%. [ABSTRACT FROM AUTHOR]

• Develop new self-assembled Ni/Co phosphides composite spheres. • Carbon nanospheres via a hydrothermal process and effective manner. • Exhibit excellent HER electrocatalytic activity. • Significant potentials in composite electrocatalyst design. Because of their high catalytic activity and abundant resources, nonprecious transition metal phosphides are favorable substitutes for noble metals as hydrogen evolution reaction (HER) electrocatalysts. In this work, self-assembled Ni/Co phosphide composite N-doped carbon spheres were successfully prepared via a hydrothermal process, which had abundant exposed active sites for the HER. The as-obtained samples exhibited excellent electrocatalytic activity for the HER with an overpotential of only 160 mV (vs. RHE) at a current density of 10 mA cm−2 in a 0.5 M H 2 SO 4 solution and a comparatively low Tafel slope (57 mV dec−1). Additionally, the Ni 2 P/CoP spheres also show good stability after 120 h and 5000 cycles of a cyclic voltammetry test. Their highly efficient catalytic activity for the HER is attributed to the specific spherical structure, which provides exposed Ni 2 P and CoP for favorable adsorption and desorption of hydrogen. Therefore, nonprecious transition metal phosphide spheres may provide a promising strategy to improve the catalytic activity of HER electrocatalysts. [ABSTRACT FROM AUTHOR]

Highlights from the article: Hydrogen Evolution: Embedding RhPx in N, P Co-Doped Carbon Nanoshells Through Synergetic Phosphorization and Pyrolysis for Efficient Hydrogen Evolution (Adv. Funct. Keywords: carbon nanoshells; hydrogen evolution reaction; phosphorization; pyrolysis; RhPx Pyrolysis, hydrogen evolution reaction, phosphorization, carbon nanoshells, RhPx.