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• BiOI is an excellent connector between ZnFe 2 O 4 and AgI to form a double Z-type heterojunction structure ZnFe 2 O 4 /BiOI/AgI composite through precise electronic regulation. • The existence of a double Z-heterojunction structure and Ag0 makes the electrons on the interface transfer and separate effectively. • Rich oxygen vacancies also provide more active sites for photocatalysis and photo-Fenton process. As a bridge, BiOI nanosheets connect ZnFe 2 O 4 nanoparticles and AgI clusters (∼300 nm) via hydrothermal-coprecipitation. A ternary composite with a double Z-type heterojunction structure is obtained through precise electronic regulation. Compared with ZnFe 2 O 4 and ZnFe 2 O 4 /BiOI, the photo-Fenton degradation RhB of ZnFe 2 O 4 /BiOI-AgI-3 samples is obviously improved under simulated sunlight. Rich oxygen vacancies also provide more active sites for photocatalysis and photo-Fenton process. The main active specie in photo-Fenton degradation is ·OH. The existence of a double Z-heterojunction structure and Ag0 makes the electrons on the interface transfer and separate effectively. Notably, the intensity of PL luminescence ZnFe 2 O 4 /BiOI/AgI is lower than that of ZnFe 2 O 4 and ZnFe 2 O 4 /BiOI because of reducing the recombination rate of photogenerated carriers. ZnFe 2 O 4 /BiOI/AgI composites have excellent stability of photo-Fenton degradation. Furthermore, the formation of a built-in electric field inhibits the recombination of electron-hole pairs, enhances visible light absorption, results in improving the efficiency of ternary composite materials to degrade pollutants. [Display omitted] [ABSTRACT FROM AUTHOR]

Reasonable construction of multi-pore heterogeneous structures and enhancement of synergistic interaction between metal ions are important means to improve the performance of supercapacitors. This work selected metal organic frameworks (MOF) as the sacrificial template, and Se-doped needle-like nanosphere heterostructures Se-CoSe 2 @ZnSe were successfully prepared by in situ growth and selenization treatment. The specific capacity of the Se-CoSe 2 @ZnSe-5 (CZS-5) electrode is up to 2469.12 F g−1 at 1 A g−1, and the capacity retention rate of 3000 cycles at a current density of 10 A g−1 is 85.39 %. The CZS-5//AC hybrid supercapacitor has a high power density of 1280.00 W kg−1 at an energy density of 68.88 Wh kg−1. The excellent electrochemical properties are attributed to the construction of Se-CoSe 2 @ZnSe heterostructure of needle-shaped nanospheres enhances the synergy between Zn and Co ions; the doping of selenium effectively improves the conductivity of the electrode material; selenium vacancies produced during selenization increase the activity of the active site. In addition, the density functional theory (DFT) calculation shows that Se-CoSe 2 @ZnSe-5 has higher density of states (DOS) near the Fermi energy level, which provides additional theoretical support for the improvement of electrochemical performance. • Se-CoSe 2 @ZnSe is needle-like nanosphere with ZIF-8 as the core, which can effectively alleviate structural collapse. • Se-CoSe 2 @ZnSe heterojunction structure effectively promotes charge rearrangement and builds internal electric field. • The selenium-rich structure effectively improves the electrical conductivity and the electron/ion transfer rate. • DFT provides theoretical support for the improvement of electrochemical performance. [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]