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The heterojunction structure photocatalysts are very promising for photocatalytic degradation dyes to resolve the organic industrial wastewater. In this work, an effective and solar light‐driven Z‐scheme heterojunction photocatalyst CAS/ZnO was prepared by two steps microwave irradiation method. The ZnO nanosheets were successfully compounded with CAS tetragonal particles aggregate. As the ZnO concentration increased, the absorbance decreased but the specific surface area increased. Rhodamine B (RhB) was tested for photodegradation by photocatalysts under a solar simulation in 120 min, and 3 M displayed the highest degradation rate (100 %), highest rate constant (0.021 min−1) and optimum stability. Furthermore, the main reactive species were superoxide radicals (O2−.) and hydroxyl radicals (HO⋅). Also, mechanism of the Z‐scheme migration of photon‐generated carrier and photocatalytic degradation was proposed. This paper provides a new Z‐scheme heterojunction CAS/ZnO photocatalyst for the treatment of organic pollutants. [ABSTRACT FROM AUTHOR]

Photocatalytic removal of hexavalent chromium (Cr(VI)) based on semiconductor is important under visible light for environment and energy. Herein, a visible light-responsive heterojunction composed of molybdenum disulfide and zinc indium sulfide was synthesized through a simple one-pot hydrothermal method to ensure full contact between the two components to efficiently improve the Cr(VI) reduction. The MoS2/ZnIn2S4 composites build heterojunctions between MoS2 and ZnIn2S4 to inhibit recombination of photogenerated holes and electrons and provide the reaction sites to trap photogenerated electrons to participate in the reduction of Cr(VI). The highly efficient reduction of Cr(VI) was obtained by adjusting the proportion of molybdenum disulfide. It demonstrates that the 0.5 wt% MoS2/ZnIn2S4 composite microstructures show the highest degradation rate of 0.1989 s−1 under visible light irradiation, 1.7 times of bare ZnIn2S4. Moreover, the MoS2/ZnIn2S4 showed excellent stability during photocatalytic recyclable processes. This work encourages researchers to remove Cr(VI) by constructing effective heterojunction structures. [ABSTRACT FROM AUTHOR]

The conveniently recoverable photocatalyst with self-floating and photothermal performance has attracted considerable attention. Herein, AgI/UiO-66-NH 2 was anchored on carbonized wood (CW) via a facile solvothermal and ion exchange deposition process. The catalytic properties and performance of the fabricated heterojunction were systematically characterized. The high-resolution transmission electron microscopy confirmed AgI/UiO-66-NH 2 was anchored on CW surface. The X-ray photoelectron spectroscopy revealed the shift of Zr 3d and Ag 3d, proving the heterojunction formation of samples. The heterojunction exhibited the strong UV adsorption peaks between 400 and 800 nm. The infrared photothermal analysis showed the heterojunction (41.2 °C) can adsorb more heat than AgI/UiO-66-NH 2 (31.2 °C) within 15 min visible light irradiation. As the floating carrier, CW enhanced the adsorption and utilization of sunlight. More than 96% of Rh B were degraded within 150 min with irradiation when the heterojunction was applied, and above 85% degradation rate were preserved after 6 cycling recycles, confirming its outstanding stability. Conclusively, this study paved a new pathway for fabricating the potential of easy recyclability and high stability of AgI/UiO-66-NH 2 @CW from biomass for wastewater treatment. [Display omitted] • AgI/UiO-66-NH 2 @CW was synthesized via a facile two-step procedure. • Carbonized wood solved the aggregating disadvantages of powder catalyst. • AgI/UiO-66-NH 2 @CW has good photocatalytic performance and recyclability. • The active species during the degradation process were identified as h+ and ∙O 2 −. [ABSTRACT FROM AUTHOR]

• TiN-Al 2 O 3 -Cr gradient layer is introduced to tailor residual stress of CZTSSe. • 60 nm sputtered gradient layer contributes the best heterojunction characteristic. • Gradient layer introduced device exhibits more satisfying bending stability. In an effort to promote the mechanical endurance of flexible Cu 2 ZnSn(S,Se) 4 (CZTSSe) solar cells, a convenient and effective strategy for introducing a TiN-Al 2 O 3 -Cr gradient layer is proposed, which can effectively tailor the residual stress and improve the heterojunction characteristic of solar cell. Benefitted from the optimum TiN-Al 2 O 3 -Cr gradient layer with 60 nm, CZTSSe presents a released residual stress of −3.33 GPa and an optimized heterojunction characteristic with the CBO of −0.28 eV. Furthermore, the PCE of flexible device is remarkably improved from 3.31 % to 5.01 %, which can maintain 85 % of the original efficiency after harsh bending. The proposed gradient layer strategy may pave a thriving way for congener flexible and portable cells. [ABSTRACT FROM AUTHOR]

Realizing flexible Cu 2 ZnSn(S,Se) 4 (CZTSSe) thin film solar cell with high efficiency and excellent mechanical durability has always been a challenging task in green demanded era. In this work, Cu 2 Cd x Zn 1-x Sn(S,Se) 4 (CCZTSSe) absorber was synthesized by selenizing Cd2+ treated CZTS precursor. Due to the powerful ability of Cd2+ soaking in boosting grain growth, the grain size of CCZTSSe was remarkably increased from nano to micron level. Cd atom actually act entering into the lattice and replaces Zn location in the post-selenization process. The band gap of CCZTSSe exhibits a decreasing trend (1.37 eV–1.29 eV) as x increases from 0 to 0.13. In comparison to CZTSSe absorber without Cd2+ soaking treatment, Cu 2 Cd x Zn 1-x Sn(S,Se) 4 (x = 0.03, 0.07 and 0.13) can establish the heterojunction with better matching effect with CdS buffer layer, demonstrating an enhanced conduction band offset (CBO). The improved heterojunction characteristic substantially prevents carrier recombination caused by interface state defects, which can be the crucial reason of the enhanced device performance. Finally, for x = 0.07, the device efficiency was optimized to 4.38%. This systematic work offers a novel solution for vital problems encountered in flexible CZTSSe thin film solar cells, which can lead to prospective applications in wearable devices. [ABSTRACT FROM AUTHOR]