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[Display omitted] Converting CO 2 into chemicals and fuels by solar energy can alleviate global warming and solve the energy crisis. In this work, CoAl-LDO/MoO 3−x (LDO/MO) composites were successfully prepared and achieved efficient CO 2 reduction under visible light. The CoAl-layered double oxides (CoAl-LDO) evolved from CoAl-layered double hydroxide (CoAl-LDH) exhibited a more robust structure, broader light absorption, and improved CO 2 adsorption ability. The local surface plasmon resonance (LSPR) effect excited by nonstoichiometric MoO 3−x broadened the photo-response range of CoAl-LDO/MoO 3−x. In addition, constructing step-scheme (S-scheme) heterojunctions could simultaneously optimize the migration mechanism of photogenerated electrons and holes, and retain carriers with strong redox ability. Therefore, the production rates of CO and CH 4 on the optimal LDO/MO composite were 7 and 9 times higher than the pristine CoAl-LDH, respectively. This work hybridizes oxidation photocatalysts and LDO-based materials to optimize the charge separation and migration mechanisms, which guides the modification of LDO-based materials. [ABSTRACT FROM AUTHOR]

Photocatalytic reduction of CO 2 is a considerable method to alleviate global warming and energy shortage. In this work, CoAl-LDH/Ni 1 Cu NP nitrogen-doped carbon composites (CA/Ni 1 Cu NP N-C) can efficiently reduce CO 2 into CO, CH 4 , and C 2 H 6 under visible light. In situ characterization techniques and theoretical calculations were employed to investigate the CO 2 evolution pathway and photocatalytic mechanism. The synergistic interaction of Cu nanoparticles and Ni single-atom sites accelerated the photogenerated charge separation and facilitated the adsorption properties of key intermediates. As a result, the yields of CH 4 and C 2 H 6 on CA/Ni 1 Cu NP N-C were achieved up to 35.245 and 25.328 μmol g−1 h−1 with electron selectivity of 40.24% and 50.61%, respectively. This work is instructive for using metal nanoparticles to optimize single-atom catalysts to promote their catalytic activity. [Display omitted] • CoAl-LDH/Ni 1 Cu NP N-C single-atom photocatalysts were synthesized. • The yields of CH 4 and C 2 H 6 were 35.245 (40.24%) and 25.328 (50.61%) μmol g−1 h−1. • The charge transfer mechanism and CO 2 evolution path were investigated. • Synergistic interaction of Cu NP and Ni 1 sites optimized the photocatalytic mechanism. [ABSTRACT FROM AUTHOR]

[Display omitted] • The CoAl-LDH/CGCNN-Metal NPs ternary photocatalysts with visible light response were prepared. • CoAl-LDH/CGCNN-Au NPs could convert CO 2 into CO, CH 4 , C 2 H 4 , and C 2 H 6 with the yields of 5.93, 17.68, 1.25 and 2.15 µmol g−1h−1. • The synergistic effect between S-scheme heterojunction and metal NPs could improve the light absorption capacity and the separation of photogenerated electron-hole pairs. Converting CO 2 into high-value products by photocatalysis can alleviate the global greenhouse effect and energy crisis. In this work, CoAl-LDH/CGCNN-Metal NPs (AC-M) ternary photocatalysts were synthesized by calcination, hydrothermal, and ultrasonic self-assembly methods. In pure water, the best sample AC-Au could convert CO 2 into CO, CH 4 , C 2 H 4 , and C 2 H 6 with the yields of 5.93, 17.68, 1.25 and 2.15 µmol g−1h−1, respectively, and exhibited good stability within 5 cycles (30 h). The synergistic effect between S-scheme heterojunction and metal NPs could broaden the composite's photo-response range and promote the separation of photogenerated carriers. Furthermore, the metal NPs could also serve as the electron-rich centers to improve the chemisorption of CO 2 and convert it into C 1 and C 2 products under visible light. This work can provide meaningful guidance for studying the efficient reduction of CO 2 to C 1 and C 2 products by S-scheme heterojunction/metal NPs ternary photocatalytic system. [ABSTRACT FROM AUTHOR]

An efficient carbon quantum dot (CQD)-modified TiO 2 /SrTiO 3 heterojunction was constructed for photocatalytic CO 2 reduction in this paper. Photogenerated electrons of SrTiO 3 transferred to TiO 2 via the transfer channel of CQDs for electron-hole recombination, while the photogenerated electrons migrated from TiO 2 to CQDs to participate in the photocatalytic CO 2 reduction reaction. Meanwhile, the up-conversion of CQDs enhanced the light harvesting ability of the catalyst and the CQDs enriched the active reaction sites. Due to the above advantages, the CO and CH 4 produce rate over 0.1-CTS reached 54.9 and 35.9 μmol g−1 h−1, respectively, which was dramatically increased compared with pure TiO 2 and pure SrTiO 3. This work proposes a feasible strategy for integrating CQDs with TiO 2 and SrTiO 3 for the optimistic cooperative effect to obtain an effective catalyst for photocatalytic CO 2 reduction. [ABSTRACT FROM AUTHOR]

• The B-TiO 2 /CuInS 2 Z-scheme heterojunction with visible light response was prepared. • B-TiO 2 /CuInS 2 could convert CO 2 into CO and CH 4 with the yields 21.39 and 4.83 µmol g−1 h−1. • Both boron doping and CuInS 2 sensitization can effectively improve the utilization of visible light. • The synergistic effect of B doping Z-scheme heterojunction optimized the separation and migration of photogenerated carriers. Photocatalytic reduction CO 2 into valuable solar fuels is a promising strategy to alleviate the greenhouse effect and the energy crisis on Earth. In this work, a B-TiO 2 /CuInS 2 photocatalyst has been synthesized through a simple hydrothermal-calcination method for efficient reducing CO 2 into CO and CH 4. Boron doping and sensitization of CuInS 2 ensure the excellent visible light response capacity of the composite catalyst. The synergistic effect between oxygen vacancies and Z-scheme heterojunction also endow the photocatalyst with strong carrier separation capability. Consequently, the optimized B-TO/CIS-2.5 sample exhibited the best CO (21.39 μmol g−1 h−1) and CH 4 (4.83 μmol g−1 h−1) production, approximately 9 and 14 times higher than that of TO and B-TO, respectively. This study provides a reliable approach for developing photocatalysts with boosted CO 2 reduction activity and high stability. [ABSTRACT FROM AUTHOR]