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Zhao Q, Zhang Y, Ke C, Yang W, Yue J, Yang X, Xiao W. Pt nanoparticles anchored by oxygen vacancies in MXenes for efficient electrocatalytic hydrogen evolution reaction. NANOSCALE 2024; 16:8020-8027. [PMID: 38545879 DOI: 10.1039/d4nr00020j] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/26/2024]
Abstract
The improvement of the hydrogen evolution reaction (HER) performance of nanomaterials is associated with the interfacial synergistic interaction and their hydrogen adsorption kinetics. Nevertheless, it is still a challenge to accelerate the proton transfer and optimize the HER kinetics by constructing Pt-supported heterostructures based on the hydrogen spillover phenomenon. Herein, oxygen vacancies on the surface of MXene nanosheets were constructed via a high-temperature annealing method, which was employed to anchor/stabilize Pt nanoparticles and fabricate a Pt/MXene heterostructure. EPR and XPS analyses verified the presence of oxygen vacancies, which could enhance the intrinsic HER activity of the MXene. The HER catalytic performance was investigated by taking into account the surface structure of the MXene affected by the annealing temperature, the concentration of Pt and the number of deposition cycles. Electrochemical results showed that Pt/MXene with higher utilization of Pt was obtained at 900 °C and 0.05 mgPt mL-1. The 0.05-Pt/MXene-900 obtained at deposition of 60 cycles in 0.5 M H2SO4 solution exhibited the optimized HER activity. The overpotential was 22 mV at a current density of 10 mA cm-2 and the Tafel slope was 42.41 mV dec-1. Furthermore, the accelerated HER kinetics was mainly due to the electron trapping ability of the MXene, small particles of Pt, as well as the enhanced charge transfer between the oxygen vacancies of the MXene and Pt. This strategy for constructing Pt-supported heterostructures based on the vacancy anchoring effects provides new ideas for the design of well-defined electrocatalysts toward the HER.
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Affiliation(s)
- Qin Zhao
- College of Science, Institute of Materials Physics and Chemistry, Nanjing Forestry University, Nanjing 210037, China.
| | - Yue Zhang
- College of Science, Institute of Materials Physics and Chemistry, Nanjing Forestry University, Nanjing 210037, China.
| | - Changwang Ke
- College of Science, Institute of Materials Physics and Chemistry, Nanjing Forestry University, Nanjing 210037, China.
| | - Weilin Yang
- College of Science, Institute of Materials Physics and Chemistry, Nanjing Forestry University, Nanjing 210037, China.
| | - Jianshu Yue
- College of Science, Institute of Materials Physics and Chemistry, Nanjing Forestry University, Nanjing 210037, China.
| | - Xiaofei Yang
- College of Science, Institute of Materials Physics and Chemistry, Nanjing Forestry University, Nanjing 210037, China.
| | - Weiping Xiao
- College of Science, Institute of Materials Physics and Chemistry, Nanjing Forestry University, Nanjing 210037, China.
- Key Laboratory of Advanced Energy Materials Chemistry (Ministry of Education), College of Chemistry, Nankai University, Tianjin 300071, China
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Zhang M, Shen L, Yu C, Li T, Bai S, Su Y, Liu Z, Li Y. Boosting the Faraday Efficiency of Electrochemical Ammonia Synthesis via the Strain Effect Induced by Interfacial Hybrid Formation between BN and Carbon Nanotubes. ACS APPLIED MATERIALS & INTERFACES 2024; 16:8832-8841. [PMID: 38327039 DOI: 10.1021/acsami.3c17530] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/09/2024]
Abstract
The electrochemical nitrogen reduction reaction (eNRR) is a highly promising alternative to the Haber-Bosch (H-B) process, but its commercial development is limited by the high bond energy of N2 molecules and the presence of the competitive hydrogen evolution reaction (HER). Here, a metal-free composite electrocatalyst of boron nitride (h-BNNs) and carbon nanotubes (CNTs) was explored through the interfacial hybridization of h-BNNs and CNTs, which showed a highly improved eNRR Faraday efficiency (FE) of 63.9% and an NH3 yield rate of 36.5 μg h-1 mgcat.-1 at -0.691 V (vs RHE). New chemical bonds of C-B and C-N were observed, indicating a strong interaction between CNTs and h-BNNs. According to the Raman spectra and the optimized model of h-BNNs/CNTs, an obvious strain effect between h-BNNs and CNTs was supposed to play a significant role in the highly improved FE, compared with the FE of h-BNNs alone (4.7%). Density functional theory (DFT) calculations further showed that h-BNNs/CNTs had lower energy barriers in eNRR, giving them higher N2 to NH3 selectivity, while h-BNNs have lower energy barriers in the HER. This work shows the important role of the strain effect in boosting the selectivity in the eNRR process.
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Affiliation(s)
- Meng Zhang
- College of Chemistry and Chemical Engineering, Xi'an University of Science and Technology, Xi'an 710054, China
| | - Lihua Shen
- College of Chemistry and Chemical Engineering, Xi'an University of Science and Technology, Xi'an 710054, China
| | - Chunxia Yu
- College of Chemistry and Chemical Engineering, Xi'an University of Science and Technology, Xi'an 710054, China
| | - Tian Li
- College of Chemistry and Chemical Engineering, Xi'an University of Science and Technology, Xi'an 710054, China
| | - Shuaishuai Bai
- College of Chemistry and Chemical Engineering, Xi'an University of Science and Technology, Xi'an 710054, China
| | - Yanwei Su
- College of Chemistry and Chemical Engineering, Xi'an University of Science and Technology, Xi'an 710054, China
| | - Zhifang Liu
- School of Integrated Circuits and Electronics, Beijing Institute of Technology, Beijing 100081, China
| | - Yuangang Li
- College of Chemistry and Chemical Engineering, Xi'an University of Science and Technology, Xi'an 710054, China
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