Predicting the electronic and optical properties of IB metals doped monoclinic BiVO₄: First principle calculations

Abstract

The effect of doping IB metals (Cu, Ag, and Au) on the photocatalytic activity of monoclinic Bismuth vanadate (BiVO 4 ) was investigated by predicting their electronic and optical properties based on the first-principle calculation. For the Cu-doped system, the formation of shallow acceptor level will narrow the band gap and trap the electrons which may enhance the separation of photoinduced carriers. And the doping of Ag has little effect on the electronic structure. However, the doping of Au will introduce a deep localized impurity level which should serve as both charge traps and recombination centers, and hinder the separation of photo-induced carriers. With incorporation of Cu, the mobility of charge carriers is enhanced due to the smaller effective mass, but the Ag and Au doping would not improve the transfer of charges. In summary, only the doping of Cu has positive effect on improving the photocatalytic activity of monoclinic BiVO 4 .

Fabrication of Porous Cu-Doped BiVO4 Nanotubes as Efficient Oxygen-Evolving Photocatalysts

“…The calculated band structures of BVO and Cu-BVO-5.0% samples are compared in Figure . The E g of the pure BVO sample is 2.16 eV, which is consistent with previous calculations but smaller than the measured value (2.29 eV) (Figure a) . For the Cu-BVO-5.0% sample, impurity levels above the VB decrease the band gap to 1.92 eV from 2.16 eV, which leads to the broader optical absorption range and enhanced utilization of the solar energy, consistent with the experimental observations (Figure b). , The total density of states (TDOS) and partial density of states (PDOS) for the BVO and Cu-BVO-5.0% samples are presented in Figure .…”

“…As shown in Figure 10a, the DOS result shows that the VB and CB for pure BVO sample are consistent with previous calculations. 24 According to the PDOS of the Cu-BVO-5.0% sample shown in Figure 10b, the existence of the impurity energy levels mainly comes from the localized Cu 3d states which is hybridized with O 2p states around the Fermi level, and it can reduce the carrier transition energy, beneficial to the limit the recombination of photoinduced carriers and the improvement of the photocatalytic activity of pure BVO. The shallow acceptor energy levels due to the Cu 2+ substituting V 5+ in BVO may act as electron traps which suppress the recombination rate of the photogenerated electron−hole pairs.…”

“…The doping method is a feasible strategy for effectively separating photogenerated charge carriers. Among various metal ion dopants investigated so far, BVO doping with Cu ion has recently been found to be a useful method to enhance the photoactivity of semiconductor photocatalysts, which can change electronic behaviors effectively, extend the light absorption edge, and expedite efficient separation of photogenerated charge carriers. − …”

Recent Progress in the Development of Semiconductor‐Based Photocatalyst Materials for Applications in Photocatalytic Water Splitting and Degradation of Pollutants

“…To explore the photocatalytic performance of doped BiVO 4 , the optical properties and electronic structures were calculated using DFT method. The effects of Au, Ag, and Cu on the photocatalytic performance of BiVO 4 was studied based on ab initio molecular dynamics method with GGA functional of PW91 for the exchange‐correlation effects and plane‐wave pseudopotential approximation to address the electron effect . For Cu‐doped BiVO 4 system, the occurrence of Cu 3d acceptor state reduce the band gap and enhance the separation of the photoinduced electron–hole pairs by acting as a trap to the photoexcited electrons.…”

Semiconductor Nanocomposites for Visible Light Photocatalysis of Water Pollutants

“…In this system the substitution of Cu 3d states at the Bi sites reduces the band gap and also act as an electron acceptor produced by photoexcitation. This doped catalyst has shown the red shift which meant it enhanced the solar light absorbance and utilization, the system has overall great water splitting capacity [116].…”