Exploiting robust and durable electrocatalysts for water splitting remains a challenge due to its sluggish oxidative half reaction. Herein, we demonstrate a facile and novel strategy to prepare an amorphous N-doped cobalt borophosphate catalyst through the calcination of zeolite-type cobalt borophosphate precursor with NH3 molecule. The as-prepared material displays robust catalytic activity and high stability within 18 h for the oxygen evolution reaction (OER) in 1.0 M KOH, e.g., an overpotential of 276 mV at 10 mA cm–2 (η @ 10 mA cm–2) and a Tafel slope of 55.8 mV dec–1, which is comparable to that of the benchmark IrO2 electrocatalyst. Its excellent catalytic activity should be ascribed to the N-dopant which could accelerate the electron transfer by tuning the electronic structure of this borophosphate; moreover, this amorphous phase with zeolite-like porous structures could increase its active site density and improve the electron and mass transport as well as facilitating gas release. Our study not only discovers a high-efficiency OER electrocatalyst but also provides a facile and practical pathway to develop promising electrocatalysts for water splitting.

It remains ac hallenge to rational design of an ew metal-organic framework (MOF)a sh ighly efficient direct electrocatalysts for the oxygen evolution reaction(OER). Herein, we developed as imple and effective method to explore an ew pillaredlayered MOF with syringic acid as ap romising OER electrocatalyst. The isostructuralm ono-, heterobimetallic MOF and N,S codoped MOF by mixing thiourea were quicklys ynthesized in a high yield under solvothermal condition. Moreover,t he optimized N,S co-doped MOF exhibits the lowest overpotential of 254 mV at 10 mA cm À2 on ag lass carbon electrode andas mall Ta fel slope of 50 mV dec À1 ,e specially,t his catalysta lso possesses long-term electrochemical durability for at least 16 h. According to the characterization, the incorporationo fNa nd S atoms into this heterobimetallic CoFe-based MOF could modify its pore structure,t une the electronic structure, accordingly,i mprove the mass and electron transportation,a nd facilitate the formation of active species, as ac onsequence, the improveda ctivity of this new N,S co-doped MOF for OER should be mainly be ascribed to higher electrochemical activation toward the actives peciesv ia in situ surface modification during the OER process.Metal-organic frameworks (MOFs), especially,p illared-layered MOFs, are rising star materials in the field of materials science because of their ultrafinep orosity,r ich active metal-sites and tunable structures, which have attracted enormousi nterest and have aw idespread application in catalysis, energy conversion technologies, and environmentally friendly technologies. [1][2][3][4][5][6][7][8][9][10][11][12][13] In particular,M OFs have been employed as high active electrocatalysts to improvet he sluggish reactionk inetics of water oxidation[ i.e.,t he oxygen evolution reaction (OER)] as one of the determine steps and the key processes in water splitting and metal-air batteries. [5][6][7][8][9][10][11][12][13] However,m ost of direct MOFs as electrocatalysts have poor long-term electrochemical durability in reaction media (strong acid or strongb ase), limiting their practical application in the field of water splitting since the long-term stability and high activity are equally importantf or catalysts. [14][15][16][17][18][19] Besides, it is criticalt hat improving MOF conductivity to enhancet heir intrinsic catalytic activity because of their low electronic conductivity and poor mass permeability.O ne effective strategy is to fabricate their derivatives through high temperature pyrolysis or chemical conversions, [20][21][22][23][24][25][26][27][28][29][30][31][32][33] such as metal oxides or hydroxides, [24][25][26] carbonbased derivatives, [27][28][29][30] and composite materials. [31][32][33] Although these derivatives exhibit improved electrocatalytic performance compared with the pristine MOFs precursors, during the pyrolysis, the intrinsics tructure of MOFs has been destroyed, simultaneously,t hese expensive organic ligands have been decomposed, severely hampering their practically largesca...

A mesoporous C,N-co doped Co-based phosphate ultrathin nanosheet derived from 2D phosphate MOFs has been explored and exhibits highly efficient OER performance.

Transition‐metal phosphates have been widely applied as promising candidates for electrochemical energy storage and conversion. In this study, we report a simple method to prepare a N, F co‐doped mesoporous cobalt phosphate with rich‐oxygen vacancies by in‐situ pyrolysis of a Co‐phosphate precursor with NH4+ cations and F− anions. Due to this heteroatom doping, it could achieve a current density of 10 mA/cm2 at lower overpotential of 276 mV and smaller Tafel slope of 57.11 mV dec−1 on glassy carbon. Moreover, it could keep 92 % of initial current density for 35 h, indicating it has an excellent stability and durability. Furthermore, the optimal material applied in supercapacitor displays specific capacitance of 206.3 F g−1 at 1 A ⋅ g−1 and maintains cycling stability with 80 % after 3000 cycles. The excellent electrochemical properties should be attributed to N, F co‐doping into this Co‐based phosphate, which effectively modulates its electronic structure. In addition, its amorphous structure provides more active sites; moreover, its mesoporous structure should be beneficial to mass transfer and electrolyte diffusion.

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Amorphous transition‐metal based materials with disordered structure are very desirable in the field of sustainable energy devices and technologies such as water‐splitting and secondary batteries due to their inherent properties of anisotropy and defects. To date, it is very urgent to explore new methods to prepare amorphous electrocatalysts. Herein, we use a simple approach to construct amorphous Co‐based selenite electrocatalyst by mechanical ball milling for oxygen evolution reaction (OER). Due to its amorphous structure as well as more active species, the obtained amorphous cobalt selenite C4S‐12 h material on the glassy carbon electrode shows superior electrochemical performance with a low overpotential of 255 mV to drive 10 mA cm−2 in 1.0 M KOH electrolyte. In addition, this catalyst also has an excellent intrinsic activity (high mass activity of 162.0 A g−1 and TOF of 0.063 s−1 at the overpotential of 350 mV) and remarkable long‐term stability (at least 32 h at a current density of 10 mA cm−2). This study offers a simple and environmentally friendly method to construct highly efficient electrocatalysts for water oxidation.