Enhancement of Charge Separation and NIR Light Harvesting through Construction of 2D–2D Bi₄O₅I₂/BiOBr:Yb³⁺, Er³⁺ Z‐Scheme Heterojunctions for Improved Full‐Spectrum Photocatalytic Performance

Abstract

Developing full-spectrum photocatalysts with simultaneous broadband light absorption, excellent charge separation, and high redox capabilities is becoming increasingly significant. Herein, inspired by the similarities in crystalline structures and compositions, a unique 2D-2D Bi 4 O 5 I 2 /BiOBr:Yb 3+ ,Er 3+ (BI-BYE) Z-scheme heterojunction with upconversion (UC) functionality is successfully designed and fabricated. The co-doped Yb 3+ and Er 3+ harvest near-infrared (NIR) light and then convert it into visible light via the UC function, expanding the optical response range of the photocatalytic system. The intimate 2D-2D interface contact provides more charge migration channels and enhances the Förster resonant energy transfer of BI-BYE, leading to significantly improved NIR light utilization efficiency. Density functional theory (DFT) calculations and experimental results confirm that the Z-scheme heterojunction is formed and that this heterojunction endows the BI-BYE heterostructure with high charge separation and strong redox capability. Benefit from these synergies, the optimized 75BI-25BYE heterostructure exhibits the highest photocatalytic performance for Bisphenol A (BPA) degradation under full-spectrum and NIR light irradiation, outperforming BYE by 6.0 and 5.3 times, respectively. This work paves an effective approach for designing highly efficient full-spectrum responsive Z-scheme heterojunction photocatalysts with UC function.

Interfacial phosphate-like “bridge” mediates bulk charge and surface oxygenated-intermediate migration for efficient photoelectrochemical water splitting

“…The regulation effect of [PO] on the interfacial energy barrier was investigated by studying the work function (WF). 32 As illustrated in Fig. 4h, the WF values of pristine ZIS and CdS are confirmed to be 5.52 eV and 5.43 eV, respectively.…”

Improved Charge Separation and CO2 Affinity of In2O3 by K Doping with Accompanying Oxygen Vacancies for Boosted CO2 Photoreduction

“…The VB XPS values ( E VB XPS ) for In 2 O 3 and KIO-3 are 1.86 and 1.97 V, respectively. According to the formula E VB vs NHE = φ + E VB XPS – 4.44, , where φ is the work function of the XPS instrument (4.5 V), the valence band maximum potentials ( E VB vs NHE ) are calculated to be 1.92 V for In 2 O 3 and 2.03 V for KIO-3. Thereby, the conduction band minimum potentials ( E CB vs NHE ) of In 2 O 3 and KIO-3 are −0.79 and −0.54 V, respectively.…”

Inorganic–Organic Dual-Ligand-Regulated Photocatalysis of CdS@ZnxCd1–xS@ZnS Quantum Dots for Lignin Valorization

“…To clarify this issue, valence band (VB)-XPS measurements were conducted to determine the VB maximum (VBM) of the CdS@Zn x Cd 1– x S@ZnS gradient-alloyed QDs capped with different organic and inorganic ligands. As illustrated in Figure S18, the OA-, MPA-, PF 6 -, and SCN-capped QDs show VBMs (vs NHEs) at 1.14, 1.80, 1.52, and 1.69 V, respectively, from the formula E VB,NHE = φ + E VB,XPS – 4.44 ( E VBM,NHE : standard hydrogen electrode potential; φ: electron work function of the XPS analyzer, the value was 4.50; E VBM,XPS : VBM value was tested by VB-XPS). , In addition, the maximum fluorescence emission peaks of four QDs are located at 464.3, 465.5, 465.9, and 465.2 nm, corresponding to the internal band gap energies of 2.67, 2.66, 2.66, and 2.67 eV for OA, MPA, PF 6 , and SCN-capped QDs. Combined with the results discussed above, the band structures of the CdS@Zn x Cd 1– x S@ZnS QDs capped with different ligands are summarized in Figure .…”