In‐Situ‐Grown Cu Dendrites Plasmonically Enhance Electrocatalytic Hydrogen Evolution on Facet‐Engineered Cu₂O

Abstract

Electrocatalytic hydrogen evolution reaction (HER) is widely regarded as one of the most efficient and sustainable strategies for hydrogen production. Up to now, most electrocatalysis research related to HER mainly focuses on stand‐alone electrocatalysis and fails to pay attention to the integration of other driving forces such as light. Herein, Cu2O nanostructures with different exposed crystal facets were synthesized by wet chemical methods for electrocatalytic HER, and it was found that the octahedral Cu2O nanostructures with exposed crystal planes of (111) (O‐Cu2O) had the best hydrogen evolution performance. Density functional theory (DFT) calculations found that the better HER performance on Cu2O (111) facets was attributed to the lower energy barrier in the Heyrovsky step. Operando Raman spectroscopy and ex‐situ characterization techniques showed that Cu2O was reduced during HER, in which Cu dendrites were grown on the surface of the Cu2O nanostructures, resulting in the better HER performance of O‐Cu2O after HER (O‐Cu2O‐A) compared with that of the as‐prepared O‐Cu2O. DFT calculations indicated that the charge transfer at the Cu2O/Cu interface enhanced its surface electron concentration. Under illumination, the onset potential of O‐Cu2O‐A is ca. 52 mV positive than that of O‐Cu2O, which is induced by the plasmon‐activated electrochemical system consisting of Cu2O and the in‐situ generated Cu dendrites. Incident photon‐to‐current efficiency (IPCE) measurements, ultraviolet‐visible (UV‐Vis) spectroscopy and X‐ray photoelectron spectroscopy (XPS) demonstrate the hot electron injection (HEI) from Cu dendrites to Cu2O. Ab initio nonadiabatic molecular dynamics (NAMD) simulations revealed that the transfer of photogenerated electrons (27 fs) from Cu dendrites to Cu2O nanostructures is faster than electron relaxation (170 fs), enhancing its surface plasmons activity, and the HEI of Cu dendrites increases the charge density of Cu2O. These make the energy level of the catalyst be closer to that of H+/H2, evidenced by the plasmon‐enhanced HER electrocatalytic activity.This article is protected by copyright. All rights reserved

In situ grown Bi2WO6@CoMoO4 layered cladding structure on carbon nanofibers by a two-step solvothermal method and Ti mesh substrate as advanced counter electrodes for dye-sensitized solar cells

“…For the sake of characterizing the crystal structure and material composition of the material, the material samples were tested by XRD. 32 As shown in Fig. 2a, the diffraction peaks at 28.30°, 32.91°, 47.14°, 55.99° and 78.22° correspond to (131), (002), (202), (133), and (406) crystal planes of Bi 2 WO 6 (JCPDS: 39-0256) crystal, respectively.…”

Understanding the Behaviors of Plasmon-Induced Hot Carriers and Their Applications in Photocatalysis

“…Subsequently, hot carriers migrate to the semiconductor materials surface to participate in redox reactions, thereby enhancing the photocatalytic efficiency (hot carrier injection enhancement mechanism). 32 However, due to insufficient understandings of hot carriers generation, transfer process, and related mechanisms, it is difficult to achieve the efficient utilization of hot carriers in photocatalysis. 33 Based on this, various advanced surface or interface characterization methods have been developed to study the generation and transfer process of hot carriers between semiconductor and plasmonic-metal, as well as catalytic reactions caused by hot carriers, such as tip-enhanced Raman spectroscopy (TERS), 34,35 transient absorption spectroscopy (TAS), 36,37 surface-enhanced Raman spectroscopy (SERS), 38,39 and Schottky diodes, 40,41 etc.…”

“…If the energy of hot carriers exceeds the Schottky barrier formed between the semiconductor and plasmonic metal, then the plasmon-induced hot carriers transfer will occur. Subsequently, hot carriers migrate to the semiconductor materials surface to participate in redox reactions, thereby enhancing the photocatalytic efficiency (hot carrier injection enhancement mechanism) …”

Regulation of polyaniline thickness and substitution position on Cu foams to optimize hydrogen evolution and ethanol oxidation performance

“…Accordingly, modern energy conversion technologies require non-noble metal catalysts with both catalytic activity and long-term stability. 7–11 Among various nonprecious electrocatalysts, copper (Cu) has received less attention in the field of electrocatalytic HER. The main reasons why metallic Cu is rarely used in HER are as follows: (i) Cu materials themselves have a weak adsorption energy for active H 2 .…”