Hierarchical loading of CuO on SiO_(2) aerogel@high crystalline TiO_(2) nanofibers for efficiently photocatalytic reduction of CO_(2) without sacrificial agent

Silica aerogel was prepared by a sol-gel method with combination of freeze drying.The aerogel was filled with TiCl4 in autoclave and used to fabricate a hierarchical structure of TiO_(2) nanofiber shell and SiO_(2) aerogel core(SiO_(2)@TiO_(2)).The TiO_(2) nanofibers with a diameter of 10-15 nm were highly crystalline and mainly grew along the(101)or(001)planes,favoring charge migration along the growth axis of the fibers.The photoluminescence(PL)emission spectra show that the TiO_(2) nanofibers exhibited much lower PL intensity than P25.The free standing TiO2 nanofibers loaded with CuO had a band gap of 3.04 eV.When CuO was hierarchically loaded on the nanofiber surface and into the aerogel core(SiO_(2)/CuO@TiO_(2)/CuO),the absorption edge significantly red shifted,and the band gap was further narrowed to 2.66 eV.Meanwhile,Fe^(3+)implanted TiO_(2) nanofibers on the aerogel surface(SiO_(2)@Fe-TiO_(2))were also fabricated in the same strategy.The CuO loaded nanofibers(SiO_(2)/CuO@Fe-TiO_(2)/CuO)had a band gap of 2.62 eV.The photocatalytic reduction of CO_(2) was performed under light irradiation by a 300 W Xe-lamp for 4 h.The methanol yield over the SiO_(2)/CuO@Fe-TiO_(2)/CuO reached~2,400 μmol·gcat^(-1) in the absence of sacrificial agent.

Catalytic reduction of low-concentration CO_2 with water by Pt/Co@NC

The reduction of low-concentration carbon dioxide with water to organic fuels is still a huge challenge. In this study, we successfully designed the partially oxidized cobalt nanoparticles coated by the nitrogendoped carbon layer(Co@NC) of 2-8 nm via a facile method and then interspersed with different amount of Pt nanoparticles. The Co@NC decorated with 1 wt% Pt exhibits the best ability for COreduction to CHand a CHproduction rate of 14.4 μmol·g·his achieved. It is worth noting that the system is carried out under low-concentration CO(400 ppm) circumstance without any sacrificial agent, which could be meaningful to the design of catalysts for atmospheric COreduction.