Characterization and photoelectrochemical evaluation of BiVO4 films developed by thermal oxidation of metallic Bi films electrodeposited

BiVO4 Photoanode with NiV2O6 Back Contact Interfacial Layer for Improved Hole-Diffusion Length and Photoelectrochemical Water Oxidation Activity

“…All electrodes showed positive slopes, suggesting that all exhibit the characteristics of n-type semiconductors. The E FB and N D values were derived from eqs and , respectively: 1 C 2 = 2 ε ε 0 A 2 e N D true( E app − E FB − k normalB T e true) N D = 2 ε ε 0 e 0 true[ normald ( 1 C 2 ) normald E true] − 1 where C is the capacitance, A is the area in cm 2 , ε is the dielectric constant, which is 68 for BiVO 4 , ε 0 is the permittivity of free space (8.85 × 10 –12 Fm –1 ), e is the charge on an electron (1.62 × 10 –19 C), N D is the charge carrier density (cm –3 ), E app is the applied potential referenced to the RHE, k B is the Boltzmann constant, and T is the temperature in K. From the intercept of Figure a, the E FB values of pristine BiVO 4 , NiV 2 O 6 /BiVO 4 , and Co-Pi/NiV 2 O 6 /BiVO 4 electrodes were calculated as 0.79, 0.73, and 0.73 V RHE , respectively. The E FB of BiVO 4 and NiV 2 O 6 /BiVO 4 photoanodes extracted from the onset of the j photo 2 – E curve (see Figure S9) agreed to a great extent with the obtained values from the M-S plots, evincing the consistency of the measured values.…”