Conversion of CO 2 into valuable chemical feedstocks through artificial photosynthesis is an effective strategy to alleviate energy and environmental issues. Herein, we have developed a novel perovskite-based catalyst via in situ growing CsPbBr 3 quantum dots (QDs) on the affinal 2D CsPb 2 Br 5 nanosheets for CO 2 photoconversion. CsPbBr 3 QDs were generated by peeling off layers from their cubic counterpart; meanwhile, CsPb 2 Br 5 nanosheets were formed by heaping up the peeled layers. The resultant dual-phase composite exhibited outstanding activity and selectivity for photocatalytic conversion of gaseous CO 2 with a CO generation rate of 197.11 μmol g −1 h −1 under 300 W Xe lamp irradiation, which is 2.5 and 1.1 times higher than that of pure CsPb 2 Br 5 or CsPbBr 3 . Importantly, the fabricated dual-phase material presented extremely high stability and was able to maintain an unchangeable CO 2 conversion rate under wet air in the consecutive 10 h of recycling test. Furthermore, attributing to the in situ assembling strategy, the close contact allowed photo-generated electrons in CsPbBr 3 QDs to transfer rapidly to CsPb 2 Br 5 , and the affluent active sites in such an architecture enabled achieving enhanced CO 2 photoconversion activity. The present work provides an attractive approach for in situ constructing a consubstantial perovskite-based composite photocatalyst to ensure great stability and excellent activity for artificial photocatalytic CO 2 conversion.

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Ag VO /mpg-C N (mesoporous graphitic carbon nitride) heterojunction photocatalysts were prepared by anchoring tiny Ag VO particles on the nanosheet of mpg-C N . The prepared Ag VO /mpg-C N heterojunctions were used to remove tetracycline (TC), a kind of antibiotics widely released into the aquatic environment under solar irradiation. Compared with pure mpg-C N and Ag VO , Ag VO /mpg-C N displayed much higher photocatalytic activity (83.2% removal rate within 90 min under visible-light irradiation). Importantly, no apparent deactivation was observed for Ag VO /mpg-C N -40 after five cycles, inferring a good reusability. As confirmed by photocurrent measurement and photoluminescence spectra, the excellent photocatalytic property of Ag VO /mpg-C N was credit to the electron-hole separation enhancement at the formed heterojunction of two semiconductors. In addition, a possible mechanism and intermediate products for the Ag VO /mpg-C N photocatalysts toward the photodegradation of TC in aqueous solution under artificial sunlight radiation were proposed based on the scavengers trapping test, ESR spectra and a high-performance liquid chromatography (HPLC) coupled with mass spectrometer (MS) analysis. This investigation provides a low cost, green and easily practical approach to remove the antibiotics in the aquatic environment.

The selective hydrogenation of nitroarenes bearing competitive reducible groups to produce functionalized amino compounds has wide application in industrial production. However, to control only reducing the target group is still a challenge. Here, Cu 2 O/M 2 Ta 2 O 6 (M=H, Li, Na, K, Ag, Bi) catalysts were prepared to evaluate their catalytic performance using 3-nitrostyrene (3-NS) as a model reaction. The results confirm pristine Cu 2 O has a highly activity to hydrogenate 3-NS but low selectivity with the coexisted products of 3-vinylaniline (3-VA), 3-ethylaniline(3-EA) and 1-ethyl-3-nitrobenzene (3-NE), whereas the independent tantalate can converse 3-NS to sole product 3-VA via absolutely preferential reduction of À NO 2 moiety but with a low conversion rate. Importantly, if combining Cu 2 O and tantalate, the activity and selectivity of the appointed product were all obviously increased. Furthermore, the hydrogenation activity of 3-NS to generate 3-VA is positively related with the catalysts' intrinsic basicity and the preferential adsorption toward À NO 2 group.