Search

Based on the fact that the photo-Fenton process can directly use solar energy to degrade various pollutants, it has received widespread attention. However, it has attracted widespread attention due to the rapid recombination of photo-generated carriers and the low light response range. Therefore, the construction of a Z-scheme heterojunction in this paper can effectively enhance the electron–hole separation, increase the reduction and oxidation potential, and enhance the redox capability of the photocatalysis. This paper reports the successful preparation of visible-light-induced ZnFe2O4/BiOI composite photocatalysis. There is a Z-scheme heterojunction structure of ZnFe2O4 and BiOI. At the same time, the PL and UV absorption spectra showed that the light absorption performance of the composite nanomaterials was enhanced, the photo-generated carrier recombination rate was reduced, and the photo-Fenton performance was also significantly improved. And the photocurrent of ZnFe2O4/BiOI is more than 27 times that of pure ZnFe2O4. In addition, ZnFe2O4/BiOI can degrade the simulated pollutant RhB 100% within 20 min under simulated sunlight. It shows that ZnFe2O4/BiOI binary composite has excellent photo-Fenton properties. In addition, ZnFe2O4/BiOI still maintains a high photo-Fenton ability after three cycles. Therefore, it has potential application prospects of the industrial photodegradation of organic pollutants. [ABSTRACT FROM AUTHOR]

Ag2S quantum dots were dispersed on the surface of SnS2 nanoflowers forming a heterojunction via in-situ ion exchange to improve photocatalytic degradation of RhB. All samples exhibit the hexagonal wurtzite structure. The size of Ag2S@SnS2 composites are ~ 1.5 μm flower-like with good crystallinity. Meanwhile, the Eg of 3% Ag2S@SnS2 is close to that of pure SnS2. Consequently, the 3% Ag2S@SnS2 composite displays the excellent photocatalytic performance under simulated sunlight irradiation with good cycling stability, compared to the pure SnS2 and other composites. Due to the blue and yellow luminescence quenching, the photogenerated electrons and holes is effectively separated in the 3% Ag2S@SnS2 sample. Especially, the hydroxyl radicals and photogenerated holes are main active species. [ABSTRACT FROM AUTHOR]

• A surface molecularly imprinted Z-type heterojunction composite photocatalyst was synthesized. • Photocatalytic materials can specifically recognize ceftriaxone sodium in water and preferentially adsorb it for photocatalytic degradation. • The selectivity depends on the holes with specific recognition ability on the surface of molecularly imprinted photocatalyst. • Molecularly imprinted photocatalyst has high stability and excellent reusability. By using the surface molecular imprinting technique, BiOCl/Bi 3 NbO 7 was used as the substrate photocatalyst and ceftriaxone sodium (CTRX) was used as the template. A molecularly imprinted photocatalyst with specific recognition and photocatalytic synergy for CTRX was synthesized. Due to the excellent photoelectric properties and the successful formation of CTRX-imprinted cavities on the imprinted layer surface. The characterization results showed that MIP-3 has the advantages of uniform particle size and high separation efficiency of photogenerated carriers. The molecularly imprinted photocatalyst MIP-3 showed remarkable synergy and selectivity in both adsorption-photocatalysis of CTRX. Further experimental results showed that MIP-3 exhibited high selective adsorption performance for both high and low concentrations of CTRX in the 30 min static adsorption experiment. About 92 % of CTRX was degraded in the 100 min light experiment, which was a large improvement compared with BiOCl/Bi 3 NbO 7. The selectivity of MIP-BNO was evaluated by comparing the degradation efficiency of MIP-3 on CTRX and chloramphenicol (CIP). Compared to non-imprinted photocatalyst NIP-BNO, MIP-3 has a higher selectivity coefficient of 2.58 and a faster degradation kinetic rate of 0.0169 min−1. The stability experiments showed that MIP-3 has good recoverability and stability during photocatalytic degradation. The mechanism of selective photocatalytic degradation of CTRX by MIP-3 was investigated by UV–visible spectroscopy, radical capture experiments, and electron spin tests. The possible degradation pathway of CTRX was also analyzed by LC-MS. In conclusion, this study confirms that the combination of surface molecular imprinting and photocatalyst has great potential to provide a promising solution for the treatment of low-level, highly toxic target pollutants in mixed wastewater. [ABSTRACT FROM AUTHOR]

[Display omitted] • A Z-scheme Bismuth iodide/Bismuth niobate heterojunction was synthesized. • Photodegradation activity was rely on the interface structure of the photocatalyst. • Interface was continuously transitional with a proper molar ratio of the Nb and Bi. • DFT analysis and the Fukui index was used to explore the degradation pathway. A direct Z-scheme bismuth iodide/bismuth niobate (BiOI/BiNbO) heterojunction photocatalysts with a different molar ratio of Bi/Nb were prepared. The structural and photoelectrical properties of these as-prepared samples were investigated, photocatalytic activity and different effect factors were evaluated. The experiment results indicated that the highest RhB degradation efficiency was that of the sample with Bi/Nb = 0.7, bringing a lower interface resistance that facilitate the separation and transportation of photogenerated carrier. Furthermore, active species trapping experiments suggested that •OH was the most contributor responsible for the RhB photocatalytic process. The photodegradation mechanism and a reasonable degradation pathway were further proposed by DFT theoretical calculation. [ABSTRACT FROM AUTHOR]