Electrodes composited by bisbenzimidazole silver(I) coordination polymers as electrocatalysts for hydrogen evolution and H2O2-sensing

• Published in: Inorganica Chimica Acta 2024-09, Vol.570, p.122164, Article 122164
• Main Authors: Lv, Yue, Gao, Wei, Zhang, Jiaqi, Fei, Cailing, Wu, Zhengwei, Wu, Huilu
• Format: Article
• Language: English
• Subjects: Composite electrodes; Electrocatalysis; H2O2-sensing; Hydrogen evolution reaction; Silver(I) coordination polymer
• ISSN: 0020-1693; 1873-3255
• DOI: 10.1016/j.ica.2024.122164

Two new silver(Ⅰ) coordination polymers (CPs) were prepared under hydrothermal conditions and structurally characterized. The CPs 1–2 both exhibit binuclear 1D “square waveform” chain structure. Electrocatalytic hydrogen evolution reaction (HER) of carbon paste composite electrodes (CPCEs 1–2) prepared by mixing graphite powder with coordination polymers were investigated in 0.5 M H2SO4 electrolyte. The results prove that CPCEs 1–2 could effectively catalyze and accelerate the HER behavior. Moreover, the recognition performance of CPCEs 1–2 for H2O2 was further studied by chronoamperometry in 0.2 M PBS. The CPCE 1–2 both showed good recognition with detection limits of 128 and 27.1 μM in the response range of 0.5 μM ∼4.0 mM. [Display omitted] •Two new binuclear 1D Ag(I) CPs were synthesized and characterized.•Electrodes composited by Ag(I) CPs show effective HER and H2O2-sensing activity.•The higher HER activity of CP 1 can be attributed to more three-coordinated Ag+ ion. Two new silver(Ⅰ) coordination polymers (CPs) {[Ag2(p-HMOPhIDC)(BBP)](H2O)}n (1), {[Ag2(m-HMOPhIDC)(BBP)](H2O)}n (2) (BBP = 1,3-[bis(2,2′-benzimidazole)] propane, p-H3MOPHIDC = 2-(4-methoxyphenyl)–2H-imidazole-4,5-dicarboxylic acid, m-H3MOPHIDC = 2-(3-methoxyphenyl)–2H-imidazole-4,5-dicarboxylic acid), were prepared under hydrothermal condition and structurally characterized. The CPs 1–2 both exhibit binuclear 1D “square waveform” chain structures. Structural analysis shows that the two silver ions in CP 1 are crystallographically independent but chemically identical; whereas the two silver ions in CP 2 are crystallographically independent and chemically different. Electrocatalytic hydrogen evolution reaction (HER) of carbon paste composite electrodes (CPCEs 1–2) prepared by mixing graphite powder with coordination polymers was investigated by variable temperature linear sweep voltammetry (VT-LSV), controlled potential electrolysis (CPE) and electrochemical impedance spectroscopy (EIS) in 0.5 M H2SO4 electrolyte. It was found that the overpotential η10293K of CPCEs 1–2 positively shifted 449 and 172 mV compared with sCPCE (−966 mV), and the Tafel slope of sCPCE and CPCE 1–2 were 276, 160 and 226 mV dec-1, respectively. The results proved that CPCEs 1–2 could effectively catalyze and accelerate the HER behavior. The higher HER activity of the CPCE 1 than CPCE 2 can be attributed to the fact that CP 1 contains more three-coordinated silver ions. Moreover, the recognition performance of CPCE