Boosting solar water oxidation activity of BiVO4 photoanode through an efficient in-situ selective surface cation exchange strategy

Nature of the Ba 4d Splitting in BaTiO3 Unraveled by a Combined Experimental and Theoretical Study

“…While values below 0.3 eV are calculated for all Ba atoms of the slab with TiO 2 terminations (see Figure 4, left), two sets of values are predicted for the slab with BaO terminations (see Figure 4, right). A δ CLBE of −1.4 eV is calculated for the Ba atoms in the two terminal layers (1 and 11), while a δ CLBE below −0.2 eV is found for all the inner layers (3,5,7,9). Even though only initial state effects are considered in this theoretical approach, the calculated core level shift of ∼1.4 eV between the surface layer and the buried ones in the BaO terminated slab is in very good agreement with the experimental shift of 1.25 eV between the Ba(α) and Ba(β) components, as well as with previous results.…”

“…2 This general trend is also especially important for oxide surfaces. Hence, exchanging surface cation Bi by Co in BiVO 4 photoanodes leads to enhanced photocurrent density with superior stability, 3 polar orientations of crystals can be stabilized by top surface reconstructions or metallic configurations, 4,5 oxide surfaces may exhibit terminations dependent on the oxygen potential, 6 and even the magnetic ordering of a material may be influenced primarily by the surface magnetic long-range ordering provided that its ordering temperature is lower than in the bulk. 7 Generally speaking, the precise knowledge of the extreme surface configuration appears as a major issue and deserves detailed investigation since it can dramatically affect the macroscopic properties of a material.…”

CeO2 nanoarray decorated Ce-doped ZnO nanowire photoanode for efficient hydrogen production with glycerol as a sacrificial agent

“…[7][8][9][10] However, the fast recombination of the photoinduced charges and the back reactions of the evolved H 2 and O 2 can reduce the energyconversion efficiency. [11][12][13][14] To overcome these key issues, biomass derivatives such as those possessing hydroxyl groups, including methanol, urea, and glycerol, and organic pollutants have recently gained much attention as effective sacrificial agents that can be used to improve the H 2 production yield in PEC systems. [15][16][17] In the PEC process, the photocatalytic oxidation of the sacrificial agents can improve the charge separation by easily forming radicals (-OH) on the catalyst surface and suppressing the H 2 -O 2 back reaction.…”

Enhanced solar water splitting of BiVO4photoanodes byin situsurface band edge modulation

“…IPCE was calculated as follows: 35 IPCE = 1240 × I (mA cm −2 )/( P light (mW cm −2 ) × λ (nm))where I is the measured photocurrent density at a specific wavelength, λ is the wavelength of incident light, and P light is the measured light power density at that wavelength. Assuming 100% faradaic efficiency, the applied bias photon-to-current efficiency (ABPE) was calculated using the following equation: 38 ABPE = I (mA cm −2 ) × (1.23 − V bias ) (V)/ P light (mW cm −2 )where I is the photocurrent density, V bias is the applied potential, and P light is the incident illumination power density (100 mW cm −2 ). The electrochemical impedance spectroscopy (EIS) Nyquist plots were obtained at 1.23 V ( vs. RHE) with a small AC amplitude of 10 mV in the frequency range of 10 −2 to 10 5 Hz.…”

“…The charge separation efficiency ( η separation ) was calculated using the equation: 38 η separation = J sulfite / J abs .…”