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[Display omitted] • A novel dual p-n junction photocatalyst called NiWO 4 /CdS/ZIF-67 was synthesized. • Persulfate was activated by photogenerated electrons, Ni and Co. • •SO 4 − were the main active substances. There was no report about dual p-n junction photocatalyst activating persulfate to accelerate the photodegradation of organic pollutants until now. Therefore, there was a need to investigate dual p-n junction photocatalyst activating persulfate to accelerate photodegradation. In this paper, we synthesized a dual p-n junction photocatalyst, NiWO 4 /CdS/ZIF-67, which demonstrated superior degradation capabilities for doxycycline hydrochloride compared to pure NiWO 4 , ZIF-67 and NiWO 4 /CdS. NiWO 4 exhibited p-type semiconductor properties, while CdS and ZIF-67 exhibited n-type semiconductor properties. By combining them into a composite photocatalyst, a conventional type II heterojunction formed at the interface of the p-n junction. This design established an internal electric field at both ends, effectively separating the photogenerated electrons and holes of each individual photocatalyst. Consequently, the photocatalytic activities of the materials were maximized. To further enhance the degradation of doxycycline hydrochloride, we employed NiWO 4 /CdS/ZIF-67 to activate persulfate under visible light irradiation. The results showed that the best degradation was achieved when 0.3 mmol persulfate was added with a k-value of 0.00681 min−1. We investigated the mechanism of activation of persulfate and the degradation pathway of doxycycline hydrochloride over the dual p-n heterojunction NiWO 4 /CdS/ZIF-67 catalysts. Additionally, we evaluated the toxicity of doxycycline hydrochloride and its intermediates using toxicity evaluation software. [ABSTRACT FROM AUTHOR]

By skillfully introducing a conjugate electron donating ring into the g-C 3 N 4 framework, the as-prepared 3 wt% PPD/CN sample not only narrows the bandgap of g-C 3 N 4 , but also absorbs more solar light up to 600 nm. As a result, the optimal sample exhibited hydrogen escape under orange light (600 nm) and bare g-C 3 N 4 had almost no such performance. [Display omitted] • Benzene ring doping in the specific site of the network of g-C 3 N 4 was obtained. • It still has photoactivity that g-C 3 N 4 barely has under the orange light. • The 3 wt% PPD/CN can effectively cover more sufficient photo flux (λ = 600 nm). • The benzene ring incorporation of g-C 3 N 4 enhanced photogenerated carrier separating. Grafting π-conjugated donor units into graphitic carbon nitride (g-C 3 N 4) represents a promising alterative to improve its light absorption range and charge transfer kinetics. To this end, we here report an efficient intramolecular g-C 3 N 4 -based conjugated copolymers via the one-spot thermal copolymerization for not only reduces the bandgap to 2.56 eV and thus expand the visible-light harvesting capability, but also accelerates the separation ability of photogenerated excitons. Consequently, the copolymer of 3 wt% p-phenylenediamine with melamine exhibits extraordinary hydrogen (H 2) evolution rate of 1040 μmol g−1 h−1 under visible light. Interestingly, it still shows hydrogen production (5.29 μmol g−1 h−1) at λ = 600 nm (orange light). Systematic characterizations have proved that the optimal sample has high photocatalytic activity, due to rapid charge transfer kinetics and exciton separation. Our work sheds light on a molecular design to regulate charge-transfer dynamics among of polymeric semiconductors towards efficient solar-to-H 2 production. [ABSTRACT FROM AUTHOR]

Highlights: [•] Photocatalytic activity of the WO3 nanoplates is much higher than commercial WO3. [•] OH is proved the active species responsible for photocatalytic reactions over WO3. [•] The photocatalytic reaction mechanism of the WO3 nanoplates is confirmed. [•] The template-free hydrothermal route is facile, cost effective and can be scaled up. [Copyright &y& Elsevier]

[Display omitted] • 2D/2D MgAl LDO/N v -CN photocatalysts were designed for CO 2 RR. • The catalyst exhibits superior photocatalytic CO 2 RR activity. • The catalysts achieved the CO evolution rate of 20.47 µmol·g−1·h−1. • The synergistic of defects and Lewis sites promote CO 2 photoreduction activity. Conversion of CO 2 to CO from solar energy on semiconductors is a promising route to renewable energy, but their practicality is limited by the poor adsorption and activation of CO 2 on the semiconductor surface and the low utilization of photovoltaic carriers. Here, we construct a MgAl layered double oxide/nitrogen-deficient carbon nitride (MgAl LDO/N v -CN) nanosheets hybrid by in situ deposition of MgAl layered double hydroxide (MgAl LDH) on N v -CN nanosheets followed by subsequent calcination. The MgAl LDO serves as the surface-rich Lewis basic sites to effectively enhance adsorption of CO 2 and H 2 O, while the nitrogen defects can enhance the optical absorption of g-C 3 N 4 and improve the charge carrier separation. The optimal MgAl LDO/N v -CN has high photocatalytic activity for CO 2 reduction with a CO generation rate of 20.47 µmol·g−1·h−1 under visible light illumination, which is 6 times higher than that of bulk g-C 3 N 4. Our work highlights the significance of synergy of MgAl LDO Lewis base/acid sites and nitrogen vacancy defects in the design of efficient photocatalysts for CO 2 reduction. [ABSTRACT FROM AUTHOR]