Research / 2020 / Article / Fig 3

Research Article

Ultrathin Hematite Photoanode with Gradient Ti Doping

Figure 3

(a) Raman patterns of homogeneously doped (3.0%), gradient-doped (1.5-6.0%), and annealed gradient-doped (1.5-6.0%) PAD electrodes. The missing peak around 660 cm-1 for annealed film indicates that the annealing process at 800°C eliminates the doping-induced disorders. (b) TOF-SIMS spectrum of gradient hematite films, indicating the gradient distribution of Ti element. (c–e) XAFS spectra of hematite electrodes with different doping concentrations with (c, d) XANES spectra illustrating the change of valance states and local coordination of Fe element and (e) EXAFS spectra indicating the alteration of Fe-O bond length.