Inorganic nanocrystal-carbon composite derived from cross-linked gallic acid derivative of polyphosphazenes for the efficient oxygen evolution reaction

The development of heteroatoms doped inorganic nanocrystal-carbon composites (INCCs) has attained a great focus for energy applications (energy production and energy storage). A precise approach to fabricate the INCCs with homogenous distribution of the heteroatoms with an appropriate distribution of metal atoms remains a challenge for material scientists. Herein, we proposed a facile two-step route to synthesize INCC with doping of metal (alpha-Fe2O3) and non-metals (N, P, O) using hydrogel formed by treating hexachlorocyclotriphosphazene (HCCP) and 3, 4, 5-trihydroxy benzoic acid (Gallic acid). Metal oxide was doped using an extrinsic doping approach by varying its content and non-metallic doping by an intrinsic doping approach. We have fabricated four different samples (INCC-0.5%, INCC-1.0%, INCC-1.5%, and INCC-2.0%), which exhibit the uniform distribution of the N, P, O, and alpha-Fe2O3 in the carbon architecture. These composite materials were applied as anode material in water oxidation catalysis (WOC); INCC-1.5% electro-catalyst confirmed by cyclic voltammetry (CV) with a noticeable catholic peak 0.85 V vs RHE and maximal current density 1.5 mA.cm(-2). It also delivers better methanol tolerance and elongated stability than RuO2; this superior performance was attributed due to the homogenous distribution of the alpha-Fe2O3 causing in promotion of adsorption of O-2 initially and a greater surface area of 1352.8 m(2)/g with hierarchical pore size distribution resulting higher rate of ion transportation and mass-flux.(GRAPHICS)

Automated summary

The synthesis of heteroatoms doped inorganic nanocrystal-carbon composites (INCCs) with homogeneous distribution of metal (alpha-Fe2O3) and non-metals (N, P, O) was achieved through a facile two-step route using hydrogel formed by treating hexachlorocyclotriphosphazene (HCCP) and 3, 4, 5-trihydroxy benzoic acid (Gallic acid). Four different samples (INCC-0.5%, INCC-1.0%, INCC-1.5%, and INCC-2.0%) were fabricated, showing uniform distribution of N, P, O, and alpha-Fe2O3 in the carbon architecture. INCC-1.5% exhibited superior catalytic performance in water oxidation catalysis (WOC), with higher methanol tolerance and stability compared to RuO2, attributed to the homogeneous distribution of alpha-Fe2O3 promoting initial O-2 adsorption and higher surface area with hierarchical pore size distribution facilitating ion transportation and mass-flux.