W–N heteroatom-interface in melon carbon nitride/N-doped tungsten oxide Z-Scheme photocatalyst toward improved photocatalytic hydrogen generation activity

•Melon-structured carbon nitride/N-doped WO3 heterojunction photocatalysts have been successfully synthesized.•Both oxygen defects and nitrogen doping in tungsten oxide were achieved simultaneously during the thermal polymerization process.•The W–N heteroatom interface was developed at the heterojunction of the photocatalysts and promoted the photocatalytic activity of water-splitting hydrogen evolution.•The formation of W–N heteroatom interface led to increased electron cloud density and featured a metallic band structure in the interface.