2D-layered Ti3C2 MXenes for promoted synthesis of NH3 on P25 photocatalysts

Abstract

A kind of 2D-layered material, Ti3C2 MXenes, was successfully used as a new and efficient co-catalyst to improve the photocatalytic NH3 synthesis performance of P25, due to its large surface area/2D-layered structure, large electric capacity, excellent electrical conductivity and effective chemisorption/activation of N2 molecules. The generation yield of NH3 was improved by 5 times on the optimized sample of 6% Ti3C2 MXenes-P25 compared with pure P25 under full spectrum light irradiation, consistent with the measured both photocurrent densities and charge lifetime. The further mechanistic study showed that Ti3C2 MXenes played an important role in the separation of photogenerated electron-hole pairs by accumulating the excited electrons from the excited P25. Most importantly, Ti3C2 MXenes could dramatically improve chemisorption and activation of N2 as demonstrated by ESR spectra and DFT calculations. In addition, Ti3C2 MXenes loading on P25 could introduce oxygen vacancies in P25, also beneficial for photocatalytic NH3 synthesis. Thus this study provides an efficient and promising co-catalyst for the photocatalytic NH3 synthesis process from N2 in air

Recent Progress on Two-Dimensional Materials

“…Besides, special bonding mode and topological structure enable 2D materials to construct hybrids with a variety of materials (Cu2O, BiO, Ni2P, etc. ), achieving improved stable bonding and carrier separation efficiency [1163][1164][1165][1166][1167][1168] . For Ni2P/BP, the Ni-P bond between BP and Ni2P could act as atomic level channels for charge transfer at the interface to supply photogenerated electron efficiently for N2 reduction 1169 .…”

Microcystis@TiO2 Nanoparticles for Photocatalytic Reduction Reactions: Nitrogen Fixation and Hydrogen Evolution

“…The peak at 288.8 eV is assigned to O -C = O functional groups [48]. It is noted that the peak around 285.0 eV for C = C bond is owed to the amorphous carbon from Microcystis left in Microcystis@TiO2-550 [49].…”

“…The peak at 288.8 eV is assigned to O-C=O functional groups [48]. It is noted that the peak around 285.0 eV for C=C bond is owed to the amorphous carbon from Microcystis left in Microcystis@TiO 2 -550 [49]. The XPS survey spectra were carried out to test the binding energy of the element of the Microcystis@TiO2.…”

Progress and challenges in photocatalytic ammonia synthesis

“…More importantly, water acted as the electron donor in this study and stoichiometric O2 production was also observed, which was one of a few examples that could observe the stoichiometric reduction and oxidation products. 104 In addition to TiO2-based photocatalysts, Pt-loaded ZnO was reported as an efficient photocatalyst for N2 photoreduction which exhibited an NH3 yield rate of 860 mmol g -1 h -1 . 105 More recently, O-doped 1T-MoS2 nanosheets with amount of SVs (SV-1T-MoS2) were used as cocatalysts over CdS nanorods for the photocatalytic N2 reduction.…”