Ti3C2Tx MXene doped by W atoms for full-spectrum photofixation of nitrogen
(1. School of Materials Science and Engineering, Central South University, Changsha 410083, China;
2. State Key Laboratory of Environment-friendly Energy Materials, Southwest University of Science and Technology, Mianyang 621010, China;
3. CAS Key Laboratory of Materials for Energy Conversion, Department of Materials Science and Engineering, University of Science and Technology of China, Hefei 230026, China)
2. State Key Laboratory of Environment-friendly Energy Materials, Southwest University of Science and Technology, Mianyang 621010, China;
3. CAS Key Laboratory of Materials for Energy Conversion, Department of Materials Science and Engineering, University of Science and Technology of China, Hefei 230026, China)
Abstract: Full-spectrum photofixation of N2 with remarkable NH3 production rate of 228 μmol/(g·h) was achieved by W atoms doped Ti3C2Tx MXene (W/Ti3C2Tx-U) catalyst without sacrificial agents at room temperature. The effects of W doping and ultrasonic intercalation of Ti3C2Tx MXene were studied. Scanning transmission electron microscope, electron spin resonance spectra, X-ray photoemission spectroscopy, UV-Vis spectrophotometer, temperature programmed adsorption analyzer and density functional theory calculation were used to characterize the obtained catalysts. Results showed that Ti3C2Tx MXene harvested ultraviolet-visible and near-infrared light to generate hot electrons. In addition, the doped W atoms played an effective role in adsorbing and activating N2 molecules by donating electrons to the anti-bonding orbital of N2 molecules to elongate the bond length of N≡N.
Key words: nitrogen fixation; photocatalysis; MXene; tungsten; full-spectrum