“…Only a few metal oxides such as VO 2 ( Haiguang Zhang et al, 2019 ), Ta 2 O 5 ( Fu et al, 2019 ), Nb 2 O 5 ( Han et al, 2018 ; Kong et al, 2019 ), NbO 2 ( Huang et al, 2019 ), and ZrO 2 ( Xu et al, 2020 ) have been reported for electrocatalytic NRR, However, these metal oxides suffer from large band gap, poor light absorption capacity toward visible light, low quantum efficiency, and fast recombination rate of photogenerated excitons, restricting their applications in photocatalytic NRR. The insulating material ZrO 2 with a band gap of ∼5.0 eV ( Xu and Schoonen, 2000 ) can absorb ultrahigh UV light ( Gaggero et al, 2021 ). In addition, it possesses high mechanical strength, non-toxicity, and corrosion resistance.…”