| 1. |
- Wang, Meiyang, et al.
(författare)
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Alkali Metal Cations as Charge-Transfer Bridge for Polarization Promoted Solar-to-H2 Conversion
- 2023
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Ingår i: Advanced Functional Materials. - : Wiley. - 1616-301X .- 1616-3028. ; 33:9
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Tidskriftsartikel (refereegranskat)abstract
- Utilization of spontaneous polarization electric field of ferroelectric materials to realize the spatial separation and fast transfer of photogenerated charges has been regarded as a promising strategy to fabricate highly efficient photocatalysts. Herein, a novel heterostructure is constructed by coupling potassium poly(heptazine imide) (K-PHI) with ferroelectric BaxSr1-xTiO3 (BxST) through a facile electrostatic self-assembly strategy. The ionic species of K-PHI can neutralize the polarized charges in BxST to form intimate interfacial contact, substantially boosting the internal electric field. Notably, K+ cations intercalated into K-PHI act as charge-transfer bridge to promote migration and separation of photogenerated charge carriers. As a result, a significantly improved H2-evolution rate of 1087.4 µmol h−1 g−1 with an apparent quantum yield (AQY) of 8.05% at 420 nm is achieved over 5% K-PHI/B0.8ST, standing among the best polymeric carbon nitride-based photocatalysts reported up to date. Moreover, the extreme stability of the catalysts is evidenced by remaining outstanding catalytic performance even after storage for half a year. This strategy can be extended to other alkali metal (Na+ and Cs+) modified polymeric materials, highlighting the key role of the bridging ions in constructing polarized heterostructure, which sheds light on the design of ferroelectric-assisted photocatalysts.
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| 2. |
- Wang, Meiyang, et al.
(författare)
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Promoted photocatalytic degradation and detoxication performance for norfloxacin on Z-scheme phosphate-doped BiVO4/graphene quantum dots/P-doped g-C3N4
- 2021
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Ingår i: Separation and Purification Technology. - : Elsevier BV. - 1383-5866. ; 274
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Tidskriftsartikel (refereegranskat)abstract
- A novel kind of Z-scheme ternary heterojunctions phosphate-doped BiVO4/graphene quantum dots/P-doped g-C3N4 (BVP/GQDs/PCN) were fabricated for the visible light degradation of norfloxacin (NOR), a typical antibiotic. Compared with binary type-II heterojunction phosphate-doped BiVO4/PCN (BVP/PCN), Z-scheme BVP/GQDs/PCN exhibited promoted interfacial charge transfer efficiency and broadened visible light response range, endowing them with excellent photodegradation activity and mineralization ability in NOR degradation. A high NOR degradation rate of 86.3% with a removal rate of total organic carbon (TOC) of 55.8% can be achieved over BVP/GQDs/PCN for 120 min visible light irradiation, which is an excellent performance compared with ever reported similar photocatalysts. In particular, because of the enhanced redox ability of photogenerated charges and the generation of multiple active species (eg. [rad]OH and [rad]O2−) over Z-scheme photocatalytic system, the accumulation of highly toxic degradation intermediates was greatly inhibited, and a better detoxication performance was obtained compared to PCN and BVP/PCN. This work may shed light on the inhibition of highly toxic degradation intermediates of antibiotics by regulating the charge transfer mechanism, photocatalytic active species, and the degradation pathway of antibiotics.
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| 3. |
- Zhang, Zhenzong, et al.
(författare)
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Internal electric field engineering step-scheme–based heterojunction using lead-free Cs3Bi2Br9 perovskite–modified In4SnS8 for selective photocatalytic CO2 reduction to CO
- 2022
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Ingår i: Applied Catalysis B: Environmental. - : Elsevier BV. - 0926-3373. ; 313
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Tidskriftsartikel (refereegranskat)abstract
- This study focuses on improving photocatalytic CO2 reduction reaction (CRR) activity and modulating product selectivity. An In4SnS8/Cs3Bi2Br9-X (ISS/CBB-X) heterojunction is prepared using novel lead-free Cs3Bi2Br9 perovskite quantum dot–modified In4SnS8, which shows considerable potential as photocatalysts for CRRs under visible light. The optimised ISS/CBB photocatalyst exhibits high activity and CO selectivity with a CO yield and selectivity of 9.55 μmol g−1 h−1 and 92.9%, respectively, 3.8 and 1.5 times higher than those of pristine ISS, respectively. Moreover, the step-scheme (S-scheme) mechanism can be fully confirmed via in situ irradiated X-ray photoelectron spectroscopy, in situ electron spin resonance, femtosecond time-resolved absorption spectroscopy and density functional theory calculations. Based on in situ diffuse reflectance spectra and theoretical investigations, the ISS/CBB shows a decreased energy barrier towards CO2 reduction to CO through an adsorbed ⁕COOH intermediate. This study contributes to the further understanding of fabricating efficient S-scheme-based photocatalysts for selective CRR.
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| 4. |
- Zhang, Zhenzong, et al.
(författare)
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Tungsten oxide quantum dots deposited onto ultrathin CdIn2S4 nanosheets for efficient S-scheme photocatalytic CO2 reduction via cascade charge transfer
- 2021
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Ingår i: Chemical Engineering Journal. - : Elsevier BV. - 1385-8947. ; 428
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Tidskriftsartikel (refereegranskat)abstract
- A novel S-scheme photocatalytic heterojunction composite nanomaterial is developed by integrating zero-dimensional WO3 quantum dots (WQDs) on two-dimensional ultrathin CdIn2S4 (CIS) nanosheets with the aim of fostering carrier separation, enhancing the performance of carrier interface transport, minimizing carrier distance transport, and achieving effective photocatalytic CO2 reduction. The composite photocatalyst WQDs/CdIn2S4 (WCIS) allows for the efficient photocatalytic reduction of CO2 to CO and CH4, as shown by product analysis and isotopic measurement. The photogenerated electrons in WQDs recombine with the holes in CIS nanosheets, and the left electrons in CIS have stronger CO2 reduction abilities. The highest yields of CO and CH4 achieved with the WCIS photocatalyst are 8.2 and 1.6 μmol g-1h−1 ––2.6 and 8 times higher than those for CIS, respectively. Moreover, the S-scheme WCIS possesses a stable crystal structure and recycling ability. Finally, the S-scheme charge transfer path on the WCIS composite is proposed according to theoretical calculation, in-situ irradiated X-ray photoelectron spectroscopy, and electron paramagnetic resonance (ESR) analyses.
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