Enhancing interfacial charge transfer in a WO₃/BiVO₄ photoanode heterojunction through gallium and tungsten co-doping and a sulfur modified Bi₂O₃ interfacial layer

Abstract

Photoanodes containing a WO3/BiVO4 heterojunction have demonstrated promising photoelectrochemical water splitting performance, but the ability to effectively passivate the WO3/BiVO4 interface has limited charge transport and collection. Here, the WO3/BiVO4...

Enhanced Photocatalytic Production of H2O2 through Regulation of Spatial Charge Transfer and Light Absorption over a MnIn2S4/WO3 (Yb, Tm) Z-Scheme System

“…The high-resolution XPS spectra of W, O, Yb, Tm, Mn, In, and S elements are shown in Figure b–h. In the W 4f XPS spectrum, the characteristic peaks at 35.2 and 37.3 eV are attributed to W 6+ , and the characteristic peaks at 34.8 and 37 eV are assigned to W 5+ . − In Figure c, the O 1s spectrum is deconvoluted into two characteristic peaks at 530 and 531.5 eV, which are attributed to the W–O bond and surface hydroxyl groups, respectively. , As shown in Figure d, the characteristic peaks at 188.7 and 189.2 eV correspond to Yb 4d 3/2 and Yb 4d 5/2 , respectively, , , and the characteristic peak at 178.9 eV of Tm 4d is observed in Figure e, , indicating the doping of Yb and Tm elements in the photocatalyst system. The Mn 2p spectrum is displayed in Figure f and presents the characteristic peaks attributed to Mn 2+ (640.9 and 652.5 eV) and Mn 4+ (644.3 and 653.7 eV). , The In 3d characteristic peaks (Figure g) at 444.4 (In 3d 5/2 ) and 452 eV (In 3d 3/2 ) demonstrate the chemical state of In 3+ . , The energy difference between S 2p 1/2 (162.2 eV) and S 2p 3/2 (161 eV) in Figure h is calculated as 1.2 eV, revealing S 2– in the hybrid photocatalyst. , As shown in Figures S3 and S4, in comparison with those of WO 3 , the XPS spectra of W and O elements of MnIn 2 S 4 /WO 3 and MnIn 2 S 4 /WO 3 (10Yb, 5Tm) – 1 have no obvious change, indicating the great stability of WO 3 without etching/defect formation during the hydrothermal synthesis of the composite photocatalytic system.…”

“…39−41 In Figure 1c, the O 1s spectrum is deconvoluted into two characteristic peaks at 530 and 531.5 eV, which are attributed to the W−O bond and surface hydroxyl groups, respectively. 42,43 As shown in Figure 1d, the characteristic peaks at 188.7 and 189.2 eV correspond to Yb 4d 3/2 and Yb 4d 5/2 , respectively, 44,4544,45 and the characteristic peak at 178.9 eV of Tm 4d is observed in Figure 1e, 46,47 indicating the doping of Yb and Tm elements in the photocatalyst system. The Mn 2p spectrum is displayed in Figure 1f and presents the characteristic peaks attributed to Mn 2+ (640.9 and 652.5 eV) and Mn 4+ (644.3 and 653.7 eV).…”

Review on BiVO4-Based Photoanodes for Photoelectrochemical Water Oxidation: The Main Influencing Factors

“…One approach for solving the low η sep is to use two separate materials for space separating generated electrons and holes, such as a heterojunction, resulting in a beneficial enhancement of the charge carrier lifetime . Constructing a heterojunction of BiVO 4 has been confirmed to effectively improve the η sep of BiVO 4 photoanodes such as WO 3 /BiVO 4 , ,, MoS 2 /BiVO 4 , TiO 2 @BiVO 4 , Co 3 O 4 /BiVO 4 , and BiVO 4 /ZnO junction . The built-in electric field in a heterojunction can enhance the electron transfer and result in excellent separation of the electron–hole pairs .…”

Efficient and Stable MoOX@Mo-BiVO4 Photoanodes for Photoelectrochemical Water Oxidation: Optimization and Understanding

“…Therefore, the TOF-SIMS depth profile unambiguously confirmed the presence of Mo + and MoO X − ions that were inserted and that chemically bonded with the BiVO 4 photoanode. 33,34 The three-dimensional (3D) visualization of the TOF-SIMS profiles indicated a homogeneous distribution of ions in the 2% Mo-BiVO 4 thin film (Figure 2b). Subsequently, BiVO 4 + , Bi + , V + , VO − , Mo + , MoO 3 − , and O − ions were detected in the structure for geochemical applications, as depicted in Figure S3a− Figure 3a presents the XRD patterns of the pure BiVO 4 and MoO X @2% Mo-BiVO 4 photoanodes.…”