The investigation of high-efficiency nonprecious electrocatalysts for hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) is of great significance for renewable energy technologies. Here, we provide a successive hydrothermal, oxidation, and phosphidation method to fabricate a 3D nest-like ternary NiCoP/ carbon cloth (CC) electrocatalyst with superior catalytic activity and stability toward HER/OER. Nest-like NiCoP/CC requires overpotentials of 44 and 62 mV to reach the current density of 10 mA cm −2 in acidic and alkaline media, respectively, toward HER. For OER, the NiCoP/CC exhibits high active and durable performance with an overpotential of 242 mV at current density of 10 mA cm −2 in alkaline solutions. Furthermore, the practical application of NiCoP/CC as a bifunctional catalyst for overall water splitting reaction yields current densities of 10 and 100 mA cm −2 at 1.52 and 1.77 V, respectively.

Searching for non-noble metal based electrocatalysts with high efficiency and durability toward hydrogen evolution reaction (HER) is vitally necessary for the upcoming clean and renewable energy systems. Here we report the synthesis of CoP nanoparticles encapsulated in ultrathin nitrogen-doped porous carbon (CoP@NC) through a metal-organic framework (MOF) route. This hybrid exhibits remarkable electrocatalytic activity toward HER in both acidic and alkaline media, with good stability. The experiment and theoretical calculation reveal that the carbon atoms adjacent to N dopants on the shells of CoP@NC are active sites for hydrogen evolution, and CoP and N dopants synergistically optimize the binding free energy of H* on the active sites, which results in a higher electrocatalytic activity than its counterparts without nitrogen doping and/or CoP-encapsulation.

The search for highly efficient platinum group metal (PGM)‐free electrocatalysts for the hydrogen oxidation reaction (HOR) in alkaline electrolytes remains a great challenge in the development of alkaline exchange membrane fuel cells (AEMFCs). Here we report the synthesis of an oxygen‐vacancy‐rich CeO2/Ni heterostructure and its remarkable HOR performance in alkaline media. Experimental results and density functional theory (DFT) calculations indicate the electron transfer between CeO2 and Ni could lead to thermoneutral adsorption free energies of H* (ΔGH*). This, together with the promoted OH* adsorption strength derived from the abundance of oxygen vacancies in the CeO2 species, contributes to the excellent HOR performance with the exchange current density and mass activity of 0.038 mA cmNi−2 and 12.28 mA mgNi−1, respectively. This presents a new benchmark for PGM‐free alkaline HOR and opens a new avenue toward the rational design of high‐performance PGM‐free electrocatalysts for alkaline HOR.

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 ...

A Co-based hybrid electrocatalyst with a N-doped carbon nanoframe composed of hollow Co NPs interlinked by CNTs is synthesized by annealing CNT inserted ZIF-67. This resultant unique 3D hybrid with highly exposed active sites and good conductivity exhibits superior performance for overall water-splitting.