Huihui Li,Xiaoyong Wu,Shu Yin,Kenichi Katsumata,Yuhua Wang
Novel g-C 3 N 4 /rutile-brookite TiO 2-x N y composite photocatalysts were fabricated through a facile solvothermal approach. The effect of rutile phase TiO 2 with brookite TiO 2 and g-C 3 N 4 on the photocatalytic activity of g-C 3 N 4 /nitrogen-doped TiO 2 composite was studied. The photocatalytic performance of the photocatalyst was evaluated by measuring the degradation of NO gas under visible and UV light irradiation. It is suggested that g-C 3 N 4 /rutile-brookite TiO 2-x N y forms a Z-scheme photocatalytic system, which shows improvement on the photocatalytic activity than that of g-C 3 N 4 /single brookite TiO 2-x N y . By importing rutile phase TiO 2-x N y , the photogenerated electrons can efficiently transfer from rutile TiO 2 to g-C 3 N 4 , which results in the separation of electron and hole pairs, enhancing the photocatalytic ability. However, single brookite TiO 2-x N y can not remove the photogenerated electrons efficiently and the photocatalytic performances of composites decrease with g-C 3 N 4 amount increase.
Mengke Liu,Yingnan Zhao,Huawang Zhao,Xianghui Li,Yuhan Ma,Xin Yong,Hong Chen,Yongdan Li
A number of M-Cu-ZSM-5 (M = La, Ni, La-Ni) samples were prepared via an aqueous solution ion-exchange method. The co-doping with Ni and La into a Cu-ZSM-5 catalyst enhanced the NO decomposition activity in a temperature range 350–550 °C. The characterization results indicate that doping with La effectively improved the dispersion of the Cu species forming more Cu 2+ ions in the sample, while the effect of Ni is likely to facilitate the implantation of Cu 2+ to form (Cu 2+ -O 2– -Cu 2+ ) 2+ dimers. The synergistic effect of La and Ni contributes to the increased (Cu 2+ -O 2− -Cu 2+ ) 2+ content in the co-doped sample, thus enhancing the NO decomposition activity.
Xiao Tan,Suitao Qi,Guangxu Cheng,Chunhai Yi,Bolun Yang
As the ideal NO removal technology, the biggest challenge associated with the direct catalytic decomposition of NO is the development of highly active deNOx catalysts at low temperatures. Herein, a composite metal catalyst, Rh(0.2)/NC-MnFe, was prepared via impregnation for the low-temperature direct decomposition of NO, which exhibited 99.6% NO conversion and 63% N2 selectivity at 150 °C, and nearly 100% NO conversion and 98% N2 selectivity at 200 °C. The characterization results showed that the Rh(0.2)/NC-MnFe catalyst possessed a regular nanocage structure, good crystallinity, and suitable specific surface area. Its excellent low-temperature activity was attributed to the transfer of the dissociated O of NO from the Rh active site to the NC-MnFe support, which effectively inhibited the deactivation of Rh. The mechanism analysis indicated that NO adsorbed on the Rh(0.2)/NC-MnFe catalyst surface can generate NO2− and NO3−, and then the adsorbed NO together with NO3− is converted to NO2− species accompanied by the release of N2O. At last, NO2− is decomposed to N2.