Fig. 5: In situ structural evolution of Ni sites in photocatalytic 2e- ORR.
From: Developing Ni single-atom sites in carbon nitride for efficient photocatalytic H2O2 production
a Ni K-edge XANES spectra of NiSAPs-PuCN during photocatalytic 2e- ORR in Ar or O2 saturated aqueous solution at room temperature. The inset is the enlarged Ni K-edge XANES spectra. b FT-EXAFS spectra of NiSAPs-PuCN under in situ operation. c Schematic diagram of Ni sites structure evolution of NiSAPs-PuCN in the photocatalytic 2e- ORR. d Optimized structures and charge difference density of adsorbed O2 molecule on NiSAPs-PuCN (The isosurface value is 0.0016 eV Å−3, electron accumulation and consumption are indicated in yellow and blue, respectively). e First-shell fitting of FT-EXAFS spectra for NiSAPs-PuCN in O2 saturated aqueous solution. f, g EPR signals of ·O2- and ·OOH of the samples in the presence of DMPO. h Raman spectra of NiSAPs-PuCN recorded during the photoreaction in O2-saturated aqueous solution.
