Ultrabroad spectral absorption is required for semiconductor photocatalysts utilized for solar-to-chemical energy conversion.The light response range can be extended by element doping,but the photocatalytic performanc...Ultrabroad spectral absorption is required for semiconductor photocatalysts utilized for solar-to-chemical energy conversion.The light response range can be extended by element doping,but the photocatalytic performance is generally not enhanced correspondingly.Here we present a solid alkali activation strategy to synthesize near-infrared(NIR)light-activated carbon-doped polymeric carbon nitride(A-cPCN)by combining the copolymerization of melamine and 1,3,5-trimesic acid.The prepared A-cPCN is highly crystalline with a narrowed bandgap and enhanced efficiency in the separation of photogenerated electrons and holes.Under irradiation with NIR light(780 nm≥λ≥700 nm),A-cPCN shows an excellent photocatalytic activity for H_(2)generation from water with rate of 165µmol g^(−1)h^(−1),and the photo-redox activity for H_(2)O_(2)production(109µmol g^(−1)h^(−1))from H_(2)O and O_(2),whereas no observed photocatalytic activity over pure PCN.The NIR photocatalytic activity is due to carbon doping,which leads to the formation of an interband level,and the alkali activation that achieved shrinking the transfer distance of photocarriers.The current synergistic strategy may open insights to fabricate other carbon-nitrogen-based photocatalysts for enhanced solar energy capture and conversion.展开更多
Perovskite nanocrystals （NCs） have strong nonlinear optical responses with a number of potential applications, ranging from upconverted blue-lasing to the tagging of specific cellular components in multicolor fluore...Perovskite nanocrystals （NCs） have strong nonlinear optical responses with a number of potential applications, ranging from upconverted blue-lasing to the tagging of specific cellular components in multicolor fluorescence microscopy. Here, we determine the one-photon linear absorption cross section of two kinds of blue-emitting perovskite NCs, i.e., CsPbCl3 and CsPb（C10.53Br0.47）3, by utilizing femtosecond transient absorption spectroscopy. The wavelength-dependent nonlinear refraction and two-photon absorption have been measured at wavelengths from 620 to 720 nm by performing Z-scan measurements. The nonlinear optical responses of CsPb（C10.53Br0.47）3 are much more pronounced than those of CsPbCl3 due to the larger structural destahilization of the former.展开更多
基金supported by the National Natural Science Foundation of China(Nos.21972094,21902105,21805191,51701127,21401190)Guangdong Special Support Program,Pengcheng Scholar Program,Shenzhen Innovation Program(Nos.JCYJ20170818142642395,JCYJ20190808142001745)the Natural Science Foundation of Guangdong Province(No.2020A1515010982).
文摘Ultrabroad spectral absorption is required for semiconductor photocatalysts utilized for solar-to-chemical energy conversion.The light response range can be extended by element doping,but the photocatalytic performance is generally not enhanced correspondingly.Here we present a solid alkali activation strategy to synthesize near-infrared(NIR)light-activated carbon-doped polymeric carbon nitride(A-cPCN)by combining the copolymerization of melamine and 1,3,5-trimesic acid.The prepared A-cPCN is highly crystalline with a narrowed bandgap and enhanced efficiency in the separation of photogenerated electrons and holes.Under irradiation with NIR light(780 nm≥λ≥700 nm),A-cPCN shows an excellent photocatalytic activity for H_(2)generation from water with rate of 165µmol g^(−1)h^(−1),and the photo-redox activity for H_(2)O_(2)production(109µmol g^(−1)h^(−1))from H_(2)O and O_(2),whereas no observed photocatalytic activity over pure PCN.The NIR photocatalytic activity is due to carbon doping,which leads to the formation of an interband level,and the alkali activation that achieved shrinking the transfer distance of photocarriers.The current synergistic strategy may open insights to fabricate other carbon-nitrogen-based photocatalysts for enhanced solar energy capture and conversion.
基金Shenzhen Basic Research Project of Science and Technology(JCYJ2015032414171163,JCYJ20170302142433007)National Natural Science Foundation of China(NSFC)(11404092,11404219,11574130)
文摘Perovskite nanocrystals （NCs） have strong nonlinear optical responses with a number of potential applications, ranging from upconverted blue-lasing to the tagging of specific cellular components in multicolor fluorescence microscopy. Here, we determine the one-photon linear absorption cross section of two kinds of blue-emitting perovskite NCs, i.e., CsPbCl3 and CsPb（C10.53Br0.47）3, by utilizing femtosecond transient absorption spectroscopy. The wavelength-dependent nonlinear refraction and two-photon absorption have been measured at wavelengths from 620 to 720 nm by performing Z-scan measurements. The nonlinear optical responses of CsPb（C10.53Br0.47）3 are much more pronounced than those of CsPbCl3 due to the larger structural destahilization of the former.
