Ni single atoms anchored on nitrogen-doped graphene as H2-Evolution cocatalyst of SrTiO3(Al)/CoOx for photocatalytic overall water splitting

Aluminum-doped strontium titanate SrTiO3(Al), has been demonstrated as the suitable photocatalyst for overall water splitting. Noble metals, such as RhCrOx, are widely applied to accelerate the photocatalytic hydrogen evolution. Herein, Ni single atoms anchored on nitrogen-doped graphene (Ni SA-NG) are adopted to replace noble metal as hydrogen (H2) evolution cocatalysts for SrTiO3(Al)/CoOx photocatalyst. The prepared Ni SA-NG/SrTiO3(Al)/CoOx photocatalyst exhibits remarkable activity for photocatalytic overall water splitting with the H2 evolution rate of 498 μmol g−1 h−1 and oxygen (O2) evolution rate of 230 μmol g−1 h−1, respectively. Ni SA-NG not only improves the efficiency of photogenerated charge transfer and separation through the Ti–O–C bonds acting as the electron transfer freeway, but also provides highly active sites to accelerate the surface H2 evolution rate. This research provides a valuable method to construct SrTiO3-based photocatalyst without noble metal cocatalysts. [Display omitted] •N-doped graphene confining Ni single atoms are applied as H2 evolution cocatalyst.•The Ni SA-NG/SrTiO3(Al)/CoOx is highly active for overall water splitting.•Coupling with Ni SA-NG favors photogenerated charge transfer and separation.•Ni SA-NG provides highly active sites for H2 evolution reaction.