Nitrogen-Doped Electrocatalysts, and Photocatalyst in Water Splitting: Effects, and Doping Protocols

Water splitting has been widely studied since the reaction affords hydrogen as an energetic pollutant-free fuel from the most abundant molecule. Electrolysis, and photolysis of water are reliable pathways for hydrogen generation in green conditions, in which a catalyst is in charge of the transformation, and manipulation of its structure predominantly impresses the reaction rate. In this review, we concentrated on the impacts of nitrogen doping on the catalyst activity in electrocatalytic and photocatalytic water splitting. Increasing conductivity, formation of new edges for evolution reaction, elevating surface area by prohibition from the aggregation of the support, enhancing transition metal deposition into the support, reducing activation energy of proton evolution, shrinking bandgap of photocatalysts, increasing light harvesting, and retarding charges recombination are the most significant results of the nitrogen doping on the catalysts. Moreover, the syntheses procedures were summarized herein to provide a comprehensive view for the nitrogen doping process.