Size-engineerable NiS2 hollow spheres photo co-catalysts from supermolecular precursor for H2 production from water splitting

• NiS2 hollow spheres with controllable size have been synthesized through a facile hydrothermal method.
• The synergetic effect of the Rayleigh instability and chemical nonequilibrium interdiffusion is predominant.
• The nanoscale NiS2 hollow spheres delivered a superior performance in the co-photocatalytic H2 production.

NiS2 hollow spheres with controllable size have been synthesized by a facile hydrothermal method through the exchanging reaction between rod-like supramolecular precursor and l-cysteine. Through modifying the diameter of rod-like precursor as template, accompanied by concomitant Rayleigh instability and chemical nonequilibrium interdiffusion, the size of NiS2 hollow sphere can be tuned ranging from nanosize to microsize. The hollow morphology of as-obtained product was attributed to the Kirkendall effect involving different transport rates for Ni and S ions. Owing to the relatively large specific area, the as-obtained nanoscale NiS2 hollow sphere manifest remarkable photo co-catalytic performance for H2 production, which generate 5.8 mmol of H2 gas under the irradiation of visible light after 6 h and 0.97 mmol/h of average H2 production rate, indicating superior H2 production performance of NiS2 hollow spheres.