Journal of Physical Chemistry C
·
2019
·
IF 4.309
Xiu-Rong Liu,Ruo-nan Ma,Dan Zhao,Chao Chen,Ning Zhang
Deliberately modulating the surface structure of oxide semiconductor materials was crucial to improve their photoelectronic conversion performance. Here, surface engineering of a Cu2O-based semiconductor (cubic particles in an average size of 300 nm) by redox embedding Rh with RhCl63– was attempted to get a series of Rh–Cu2O catalysts, and their photocatalytic properties were typically surveyed from dye (methyl orange, MO) photodegradation. With comprehensive characterizations, it was demonstrated that the highly dispersed and tightly integrated Rh–Cu2O interface, featuring oxidatively bonded Rh in surface layers of the Cu2O substrate, was well constructed by adjusting Rh loading from 0.04 to 0.38 wt %, exhibiting an obvious enhancement in photocatalytic performance for MO degradation compared to bare Cu2O. The measurements from photoproduction of H2, photocurrent, electrochemical impedance, and scavengers-present tests further illuminated that the Rh species bonded on the Cu2O surface in an electron-deficiency state and greatly contributed to not only improving separation efficiency of photogenerated electron/hole pairs, but also lowering the resistance to speed charge transferring along the Rh–Cu2O interface, resulting in the enhanced photocatalytic performance of Rh–Cu2O catalysts. In addition, the photocatalytic principle of Rh–Cu2O catalysts for dye degradation was also discussed. These results indicated that oxidatively bonded metal species in surface layers of Cu2O was feasible for getting an efficient charge-separation–transferring M–Cu2O interface to improve the photoelectronic conversion performance, which could be referred to as a notable system to directly engineer a semiconductor surface for advanced photoenergy applications.
研究领域:
材料科学
·
环境科学
·
化学
✓ 已验证
DOI
高影响因子
Journal of Energy Chemistry
·
2024
·
IF 14
Jinzhi Jia,Jinhua Zhang,Kailu Guo,Lanyue Zhang,Gening Du,Hao You,Junfeng Huang,Mudong Tu,Hua Li,Yong Peng,Wei Dou,Cailing Xu
Designing highly active and stable electrocatalysts of oxygen evolution reaction (OER) is one of the crucial challenges. In this study, a novel OER electrocatalyst, NiFe-MIL-53 modified with ultra-low rhodium (Rh@NiFe-MIL-53), is successfully prepared via the hydrothermal method. In-situ Raman spectroscopy and electrochemical impedance spectroscopy reveal that the doped Rh accelerates the phase transformation of NiFe-MIL-53 and the in-situ formed Rh@NiFeOOH is the actual active species. More importantly, the enhanced reversibility of electrochemical reconstruction between NiFeOOH and NiFe(OH) 2 after doping Rh is beneficial for improving the electrochemical stability of the catalyst. X-ray photoelectron spectroscopy spectra show the strong electronic interaction between single-atom Rh and Ni/Fe in Rh@NiFeOOH. Furthermore, theoretical calculations confirm that the integration of single-atom Rh into the NiFeOOH successfully reduces the band gap, regulates the d -band center ( ε d ), accelerates the charge transfer, and optimizes the adsorption behavior of oxygen-containing intermediates, thereby lowering the energy barrier of rate-determining steps. Consequently, the optimized Rh@NiFe-MIL-53 exhibits excellent OER activity (240 mV) with a small Tafel slope of 48.2 mV dec −1 and long-term durability (over 1270 h at 10 mA cm −2 and 110 h at 200 mA cm −2 ). This work presents a new perspective on designing highly efficient OER electrocatalysts.
研究领域:
材料科学
·
电化学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF MATERIALS SCIENCE-MATERIALS IN ELECTRONICS
·
2021
·Vol. 32
·期 10
·14102-14112
·
IF 2.478
Gao Ying,Zhang Jinniu,Leng Deying,Li Gang,Zhang Yuanyi,Wang Wei,Liang Qingfei,Chen Xiaorui,Lu Hongbing,Gao Jianzhi
Construction of high-performance gas sensors based on p-type metal oxides is still a big challenge. In this work, with the objective of improving the sensing properties of p-type NiO, a series of porous Rh–NiO heterojunction nanofibers with various molar ratios (Rh/Ni = 3%, 5% and 7%) are fabricated by a facile electrospinning technique. The effects of Rh content on surface area, oxygen species absorbing capability, as well as acetone sensing properties of NiO nanofibers are systematically investigated. Sensing results demonstrate that the Rh–NiO sensor with an optimal Rh amount of 5 mol% exhibits the highest p-type response of 70.10 to 200 ppm acetone at 225 °C, which is 37.9 times higher than that of pure NiO nanofiber sensor. Moreover, the 5 mol% Rh–NiO nanofibers also possess excellent acetone selectivity. The improved sensing response of Rh–NiO nanofibers is mainly attributed to the formation of ohmic contacts between Rh nanoparticles and NiO nanoparticles, facilitating the reduction of sensor resistance in air and the increase of chemisorbed oxygen capability. Chemical sensitization effect of Rh nanoparticles and increased BET surface area also contribute to the improved acetone response of Rh–NiO nanofibers.
研究领域:
材料科学
·
传感器技术
✓ 已验证
产品关联
DOI
高影响因子
Nature Communications
·
2017
·Vol. 8
·期 1
·1-7
·
IF 12.124
Lin Jin,Li Zhi,Kan Jian,Huang Shijun,Su Weiping,Li Yadong
Catalytic oxidative C–H bond functionalization reactions that proceed without requiring stoichiometric amounts of external oxidants or pre-functionalized oxidizing reagents could maximize the atom- and step-economy in chemical syntheses. However, such a transformation remains elusive. Here, we report that a photo-driven catalytic process enables decarboxylative C–H trifluoromethylation of (hetero)arenes with trifluoroacetic acid as a trifluoromethyl source in good yields in the presence of an external oxidant in far lower than stoichiometric amounts (for example, 0.2 equivalents of Na 2 S 2 O 8 ) using Rh-modified TiO 2 nanoparticles as a photocatalyst, in which H 2 release is an important driving force for the reaction. Our findings not only provide an approach to accessing valuable decarboxylative C–H trifluoromethylations via activation of abundant but inert trifluoroacetic acid towards oxidative decarboxylation and trifluoromethyl radical formation, but also demonstrate that a photo-driven catalytic process is a promising way to achieve external oxidant-free C–H functionalization reactions.
研究领域:
有机化学
·
催化
·
光化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
危险品化学品经营许可证（带存储）