activities when compared to Pt/C is highly desirable, but still remains challenging.Transition metal phosphides (TMPs) have been investigated as a new class of effective HER catalysts due to their hydrogenase-like catalytic mechanism. [7] It has been reported that the introduction of phosphorus could modify the electronic structure of metal center, resulting in optimized reversible binding of hydrogen, which is considered as the key fact for boosting HER performance. [8] Despite intensive efforts have been made to develop pH-universal TMP-based electrocatalysts with both high-activity and long-term stability, only a few of them could exhibit comparable to, or even better activities than commercial Pt/C in acidic media. Adding insult to injury, Pt-free catalyst with superior catalytic performance to Pt/C under alkaline or/and neutral media has been rarely reported. Very recently, Li's group first reported the successful synthesis of Rh 2 P nanocubes with the average size of about 4.7 nm through a solvothermal method. [9] And the obtained Rh 2 P nanocubes exhibit good HER activities both in 0.5 m H 2 SO 4 and 0.1 m KOH. On the other hand, it is known that catalytic process occurs on the surface of catalysts, thus the size of catalysts is in connection with exposed active site numbers. [10] Experiment results show that nanocatalysts with decreased size often possess higher surface area and more active sites, resulting in enhanced catalytic activity. Consequently, developing ultrasmall TMPs with narrow size distribution may boost HER activity and even superior to the stateof-the-art Pt/C. Inspired by these ideas, in this work, we report the successful colloidal synthesis of monodisperse Rh 2 P nanoparticles (NPs) with an average size of 2.8 nm as well as their superior catalytic performances toward pH-universal HER. As expected, the monodisperse Rh 2 P NPs exhibit higher HER activities than Pt/C over a wide range of pH, with overpotentials of 14, 30, and 38 mV to achieve 10 mA cm −2 in 0.5 m H 2 SO 4 , 1.0 m KOH, and 1.0 m phosphate-buffered saline (PBS), respectively. As far as we know, this is the first example of Pt-free electrocatalyst possessing higher pH-universal HER performance than the state-of-the-art commercial Pt/C. Furthermore, density functional theory (DFT) calculations indicate that the H adsorption strength of Rh 2 P is weakened to nearly zero due to the introduction of P, thereby resulting in the outstanding HER performance.The search for Pt-free electrocatalysts exceeding pH-universal hydrogen evolution reaction (HER) activities when compared to the state-of-the-art commercial Pt/C is highly desirable for the development of renewable energy conversion systems but still remains a huge challenge. Here a colloidal synthesis of monodisperse Rh 2 P nanoparticles with an average size of 2.8 nm and their superior catalytic activities for pH-universal HER are reported. Significantly, the Rh 2 P catalyst displays remarkable HER performance with overpotentials of 14, 30, and 38 mV to achieve 10 mA cm −2 ...

The search for highly efficient non-precious metal electrocatalysts toward the oxygen evolution reaction (OER) is extremely essential for renewable energy systems. Here, we report the colloidal synthesis of Fe doped NiSe, which functions as a high-performance electrocatalyst for the OER in alkaline solution. The NiFeSe catalysts are composed of urchin-like dendrites with a high number of active sites, which could provide fast transportation of electrons and electrolytes, and facile release of the evolved O bubbles during the OER catalysis. Benefitting from this unique urchin-like structure and strong electron interaction between Fe, Ni, and Se, the NiFeSe catalyst exhibits excellent electrocatalytic activity and high durability toward the OER in alkaline solution, with an overpotential of 227 mV at a current density of 10 mA cm, which is, to the best of our knowledge, higher than most of the reported selenide-based electrocatalysts.

Ultrafine monodisperse bimetallic NiPt nanoparticles with different compositions have been successfully synthesized by coreduction of nickel acetylacetonate and platinum acetylacetonate with borane-tert-butylamine in oleylamine. Among all the catalysts tested, Ni84Pt16/graphene exhibited 100% hydrogen selectivity, and marked high catalytic activity, with TOF values of 415 h(-1) at 50 °C, and 133 h(-1) at 25 °C for hydrogen generation from alkaline solution of hydrazine.

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In this study, well dispersed Cu@Co core-shell nanoparticles (NPs) on rGO surfaces were successfully synthesized via a one-step in situ procedure using methylamine borane (MeAB) as reductant under ambient conditions. The Cu@Co/rGO NPs exhibit superior catalytic activity than their alloy (CuCo/rGO) and graphene-free (Cu@Co) counterparts toward the hydrolytic dehydrogenation of ammonia borane (AB). Additionally, compared with the NPs reduced by AB, the as-synthesized Cu@Co/rGO NPs generated by the weaker reducing agent MeAB exhibit higher catalytic activities. Furthermore, the as-synthesized NPs exerted satisfactory catalytic activities and recycle stabilities for the hydrolysis of MeAB. Moreover, this general method indicates that MeAB can be used as both a potential hydrogen storage material and an efficient reductant which can be easily extended to the facile preparation of other rGO-supported metal NPs.

The exploration of efficient non-noble metal electrocatalysts for hydrogen evolution reaction has received much attention to replace commercial Pt catalyst. It is all known that cooperative coupling of appropriate non-noble...

NiSe2/FeSe2nanodendrites have been synthesized through a facile colloidal synthetic approach. Thanks to its unique 3D structure with branched architectures and the synergistic effect after Fe doping, the resulting Ni0.5Fe0.5Se2catalyst exhibits superior OER activity with an overpotential of 235 mV at a current density of 10 mA cm−2.

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