Precision Chemistry
·
2025
·
IF 6.2
Er-Fei Zhen,Bing-Yu Liu,Meng-Ke Zhang,Lu−Lu Zhang,Chen-Yu Zhang,Jun Cai,Marko M. Melander,Jun Huang,Yan-Xia Chen
Understanding how the electrolyte pH affects electrocatalytic activity is a topic of crucial importance in a large variety of systems. However, unraveling the origin of the pH effects is complicated often by the fact that both the reaction driving forces and reactant concentrations in the electric double layer (EDL) change simultaneously with the pH value. Herein, we employ the hydrogen evolution reaction (HER) at Au(111)-aqueous solution interfaces as a model system to disentangle different pH-dependent factors. In 0.1 M NaOH, the HER current density at Au(111) in the potential range of −0.4 V < ERHE < 0 V is up to 60 times smaller than that in 0.1 M HClO4. A reaction model with proper consideration of the local reaction conditions within the EDL is developed. After correcting for the EDL effects, the rate constant for HER is only weakly pH-dependent. Our analysis unambiguously reveals that the observed pH effects are mainly due to the pH-dependent reorganization free energy, which depends on the electrostatic potential and the local reaction conditions within the EDL. Possible origins of the pH and temperature dependence of the activation energy and the electron transfer coefficients are discussed. This work suggests that factors influencing the intrinsic pH-dependent kinetics are easier to understand after proper corrections of EDL effects.
研究领域:
电化学
·
催化
·
物理化学
·
表面科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Journal of the American Chemical Society
·
2024
·
IF 14.4
Yu-Qi Wang,Jiaju Fu,Yue Feng,Kaiyue Zhao,Lu Wang,Ji-Yuan Cai,Xiang Wang,Ting Chen,Fan Yang,Jin-Song Hu,Bingjun Xu,Dong Wang,Li-Jun Wan
The activity of the electrocatalytic CO2 reduction reaction (CO2RR) is substantially affected by alkali metal cations (AM+) in electrolytes, yet the underlying mechanism is still controversial. Here, we employed electrochemical scanning tunneling microscopy and in situ observed Au(111) surface roughening in AM+ electrolytes during cathodic polarization. The roughened surface is highly active for catalyzing the CO2RR due to the formation of surface low-coordinated Au atoms. The critical potential for surface roughening follows the order Cs+ > Rb+ > K+ > Na+ > Li+, and the surface proportion of roughened area decreases in the order of Cs+ > Rb+ > K+ > Na+ > Li+. Electrochemical CO2RR measurements demonstrate that the catalytic activity strongly correlates with the surface roughness. Furthermore, we found that AM+ is critical for surface roughening to occur. The results unveil the unrecognized effect of AM+ on the surface structural evolution and elucidate that the AM+-induced formation of surface high-activity sites contributes to the enhanced CO2RR in large AM+ electrolytes.
研究领域:
电化学
·
催化
·
表面科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Chemical Science
·
2026
·
IF 7.4
Yue Feng,Yu-Qi Wang,Jiaju Fu,Zi-Cong Wang,Dong Wang,Li-jun Wan
Understanding the in situ surface structure of electrodes is crucial for unraveling the synergistic mechanisms of electrolytes in interfacial electrocatalysis. Herein, using in situ electrochemical scanning tunneling microscopy (EC-STM), we unveil the electrolyte concentration-driven roughening of Au(111) surfaces under cathodic polarization. As the concentration of alkali metal cations (AM+) ([AM+]) decreases, the AM+-induced surface structure evolution proceeds from surface corrosion at 1 M, to the formation of surface pits alongside surface nanoclusters composed of released Au atoms at 0.5-0.3 M, and ultimately to the generation of pit-free nanoclusters via surface atomic migration at 0.2 M. Moreover, surface modifications modulate the electrode surface structure, enabling more pronounced structure evolution at lower bulk [AM+]. Electrochemical measurements correlate increased surface roughness with enhanced CO2 reduction reaction (CO2RR) performance. The results provide new perspective on understanding the role of AM+ in regulating the electrochemical interface, and microscopic insights into AM+ concentration-driven in situ surface structures, which is important for understanding electrolyte-mediated surface structure-activity relationships.
✓ 已验证
产品关联
DOI
PubMed
高影响因子
MOLECULES
·
2023
·Vol. 28
·期 13
·5116
·
IF 4.6
Rongyu Tang,Yang Song,Lizhi Zhang,Ziliang Shi
Herein, we demonstrate the supramolecular assemblies from a bifunctional ligand on Au(111), towards engineering two-dimensional (metal-) organic multilevel nanostructures. The bifunctional ligand employed, including two Br atoms and one carboxylic terminal, offers multiple bonding motifs with different configurations and binding energies. These bonding motifs are highly self-selective and self-recognizable, and thus afford the formation of subunits that contribute to engineering multilevel self-assemblies. Our scanning tunneling microscopy experiments, in combination with the density functional theory calculations, revealed various hydrogen, halogen and alkali-carboxylate bonding motifs dictating the different levels of the assemblies. The multilevel assembly protocol based on a judicious choice of multiple bonding motifs guarantees a deliberate control of surface-confined (metal-) organic nanostructures. Our findings may present new opportunities for the fabrication of complex two-dimensional (metal-) organic nanostructures with potential in applications of functionally diverse nanomaterials.Keywords:two-dimensional supramolecular self-assembly;metal-organic coordination;surface;scanning tunneling microscopy;density functional theory
✓ 已验证
产品关联
DOI
PubMed
高影响因子
PHYSICAL CHEMISTRY CHEMICAL PHYSICS
·
2021
·Vol. 23
·期 34
·18930-18935
·
IF 3.676
Wei Xiong,Xiang Ren,Binbin Da,Yong Zhang,Hui Zhang,Jianchen Lu,Jinming Cai
Zinc(II) tetraphenylporphyrin (ZnTPP) has very broad application prospects in the fields of supramolecular chemistry, solar cells and nanomaterials. In this paper, by using scanning tunneling microscopy (STM), we systematically investigated the ZnTPP molecule and its four derivatives formed by thermal annealing were characterized unambiguously by bond-resolved STM (BR-STM). The electronic properties of the ZnTPP molecule and its four cyclodehydrogenation products were investigated by scanning tunneling spectroscopy (STS) combined with DFT calculations. The spatial distribution of molecular frontier orbitals of four products was obtained by dI/dV mappings. This work gives rise to a full-scale investigation of ZnTPP on Au(111), which will be potentially useful in nanodevices and optoelectronics.
研究领域:
材料科学
·
表面科学
·
纳米技术
✓ 已验证
DOI
高影响因子
Journal of Materials Chemistry A
·
2020
·Vol. 8
·期 37
·19300-19308
·
IF 11.301
Jingchun Wang,Xiaoyu Qiu,Keying Su,Siyuan Wang,Jiatian Li,Yawen Tang
It remains a grand challenge to control the island growth mode because a conformal growth is theoretically more favorable, in which the lattice mismatch between the overlayer and the substrate is negligible. Herein, we report the first example of “Frank–van der Merwe” mode and “Volmer–Weber” mode of Pd atoms on Boerdijk–Coxeter-type helical Au(111) nanowires. Quantitative analyses suggest that the pH-induced faster kinetic reduction rate (1.2 × 10−2 s−1) is a crucial factor to switch the Pd-growth mode from the conformal 4-atom-layers to ultrasmall islands. As a proof-of-concept application, the VW Au@Pd HNWs exhibit outstanding ORR activity (Eonset = 1.07 V, E1/2 = 0.91 V) and stability, outperforming FM Au@Pd NWs, Au(111) NWs, Pd black, and most reported electrocatalysts. Physical characterization systematically elucidated similar components, d-band center locations, and lattice distortions of both the representative structures, giving brand-new insights into the impact of their slightly different surface microstructures. In particular, the segmented oxyphilic–anaerobic interface of the VW Au@Pd HNWs directly balances the adsorbability of the intermediates; meanwhile, the interleaved lattice orientations favor multi-directional electron transmissions to promote ORR kinetics. This finding not only challenges the conventional wisdom of lattice-matched growth but also provides an identical model for the in-depth understanding of the structure–function relationship with a focus on the growth modes.
✓ 已验证
产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）