TY  - JOUR
AU  - Li, Jun
AU  - Li, Peiyang
AU  - Ge, Shixuan
AU  - Liu, Zhongyi
AU  - Zhang, Yangyang
AU  - Liu, Bin
PY  - 2026
TI  - Engineering interfacial H-bond networks via orbital hybridization on CuBiO2−x to boost proton-coupled electron transfer for CO2-to-HCOOH electrosynthesis
JO  - Nano Research
SN  - 1998-0124
SP  - 94908687
VL  - 19
IS  - 7
AB  - The electrochemical CO2 reduction reaction (CO2RR) to formic acid (HCOOH) is constrained by slow kinetics and limited selectivity due to inefficient proton-coupled electron transfer (PCET). Herein, we synthesized Cu-doped BiO2−x (CuBiO) nanosheets to facilitate proton transfer through reconstruction of the hydrogen-bond (HB) network, thereby accelerating the PCET process. The in-situ measurements reveal that part of the 4-coordinated hydrogen-bonded water (4-HB·H2O) transforms into 2-coordinated hydrogen-bonded water (2-HB·H2O) over CuBiO during CO2RR. This reconstruction forms a linear proton transport pathway which efficiently promotes proton transport during PCET steps and concurrently inhibits the competing hydrogen evolution reaction. Density functional theory (DFT) calculations further elucidate that the Cu doping not only facilitates water dissociation into protons while inhibiting proton dimerization, but also enhances CO2 activation and reduces the energy barrier for of *CO2 → *OCHO. Ultimately, the CuBiO-6 displays highly efficient conversion of CO2 to HCOOH with a Faradaic efficiency (FE) of 92.4% and maintains stable operation for over 22 h. These findings provide a novel strategy to accelerate the PCET through regulation of interfacial HB network towards efficient CO2RR to HCOOH.
UR  - https://doi.org/10.26599/NR.2026.94908687
DO  - 10.26599/NR.2026.94908687