Surface Charge Redistribution Research Articles

In situ constructing p-n heterojunction NiCo-MOF/LDH with built-in electric field for wide response range of glucose sensing

The development of non-precious metal nanomaterial for glucose sensor with sensitive performance and broad detection range will be a great challenge. In this study, a p-n heterojunction catalyst (NiCo-MOF/LDH) is devised as an efficient electrocatalytic oxidation material for glucose detection in alkaline solutions. As an enzyme-free sensor of glucose, (NiCo-MOF/LDH) exhibits good electrochemical properties with high sensitivity of 27.76 μA mM−1 cm−2, a low detection limit of 8 µM at a signal-to-noise ratio of 3 and a wide linear range (40 μM-16 mM). The results indicate that the Mott-Schottky junction between NiCo-MOF and NiCo-LDH constructs the built-in electric field (BEF) and achieves the redistribution of surface charge. The local positive charge induced by the p-n junction allows the NiCo-MOF side to adsorb more OH−, and the local negative charge allows the NiCo-LDH side to adsorb glucose positively charged H, optimizing the adsorption reactants and key intermediates. At the same time, the sensor is successfully applied to the detection of glucose in actual sample samples. Hence, the p-n heterojunction NiCo-MOF/LDH provides a rational strategy for a non-enzymatic glucose sensing catalyst.

Edge functionalized with benzenesulfonyl groups of g-C3N4 nanosheets as a highly efficient photocatalyst for water purification

Photocatalytic water purification is a promising method for environmental remediation, but it is greatly hindered by the rapid charge carrier recombination behavior of the photocatalysts. Herein, a simple wet-chemical method is developed for grafting electron-withdrawing benzenesulfonyl groups at the edges of g-C3N4 nanosheets. These exhibited a superior and versatile photocatalytic performance on the degradation of organic contaminant, as well as disinfected Escherichia coli (E. coli) bacteria under visible light illumination. Systematic studies reveal that the grafting of benzenesulfonyl groups led to the synergic effect in ultrathin g-C3N4 nanosheets of enhancing the photogenerated charge carrier separation on surface, improving light absorption, changing electronic band structure, and causing surface charge redistribution, all of which are beneficial for enhancing the photocatalytic performance. Notably, these edge-activated g-C3N4 photocatalysts also demonstrate remarkable photocatalytic activity in the real tap water and urban wastewater, indicating their promising potential for application in real wastewater treatment.

Gamma-induced stress, strain and p-type doping in MBE-grown thin film MoTe2.

A thorough examination of the stability of a 2D MoTe2 thin film exposed to high-dose gamma radiation (γ) is addressed in this study. This study compares the film before and after irradiation (10-600 kGy dosage) to report the impact of γ radiation on the surface morphology, work function, tensile strain and charge redistribution in the MoTe2 thin film. The radiation damage to the film is monitored by optical micrographs (OM) and with atomic force microscopy (AFM) and conceptualized by thermal strain in the film. Raman spectroscopy has been used to analyze the shifting and to address the strain that arises due to irradiation in its vibrational mode. Kelvin probe force microscopy (KPFM) has been performed to evaluate the work function of the film, which increases by 0.14 eV for the 600 kGy γ-irradiated sample, implying shifting of the Fermi-level to the valence band of the spectrum and thus it results in p-type doping in the film. Owing to the reduced atomic mass and high energy of tellurium atoms, γ-irradiation causes tellurium vacancies, which lead to the formation of dangling bonds at unoccupied sites. When oxygen is adsorbed at these reactive spots, a charge-transfer mechanism takes place. This mechanism involves the transfer of electrons from the thin MoTe2 film to the adsorbed oxygen, forming oxides and causing p-type doping. Furthermore, p-doping is verified by the valence band shifting by 1.27 eV in 600 kGy in γ-irradiated samples in X-ray photoelectron spectroscopy. This comprehensive study shows how γ irradiation affects the chemical and physical characteristics of the MoTe2 thin film. Consequently, it shows that if devices integrating MoTe2 thin films are meant to be used in high-dose radiation conditions, the adsorbate concentrations, radiation shielding and required lifetimes must be carefully evaluated.

Tracking surface charge dynamics on single nanoparticles.

Surface charges play a fundamental role in physics and chemistry, in particular in shaping the catalytic properties of nanomaterials. However, tracking nanoscale surface charge dynamics remains challenging due to the involved length and time scales. Here, we demonstrate time-resolved access to the nanoscale charge dynamics on dielectric nanoparticles using reaction nanoscopy. We present a four-dimensional visualization of the spatiotemporal evolution of the charge density on individual SiO2 nanoparticles under strong-field irradiation with femtosecond-nanometer resolution. The initially localized surface charges exhibit a biexponential redistribution over time. Our findings reveal the influence of surface charges on surface molecular bonding through quantum dynamical simulations. We performed semi-classical simulations to uncover the roles of diffusion and charge loss in the surface charge redistribution process. Understanding nanoscale surface charge dynamics and its influence on chemical bonding on a single-nanoparticle level unlocks an increased ability to address global needs in renewable energy and advanced health care.

Effect of gamma radiation on the crack pattern of a styrene-acrylic emulsion dry droplet

We present findings on the influence of gamma radiation on the crack pattern of dried drops of an aqueous styrene-acrylic emulsion. An increase in the dose of gamma radiation reduces the number of cracks and expands the edge of the dried droplet. Furthermore, gamma radiation induces a reduction in the branching of the crack pattern and an increase in the frequency of cracks, with a magnitude comparable to the width of the edge of the dried droplet. The results of the infrared analysis indicated that the micelles surrounding the styrene-acrylic copolymer in the emulsion exerted a protective effect, preventing indirect damage caused by radicals formed due to water radiolysis. The results of the zeta potential and particle size measurements demonstrated that gamma radiation caused an increase in the average size of the micelles, a widening of the size distribution, and a redistribution of surface charges. Doses above 100 kGy induce a loss of emulsion stability. The effects of gamma radiation on the crack patterns were interpreted by considering the dynamics of micelle deposition at the edge of the drop during drying and the appearance of mechanical instabilities in the deposit that lead to cracks. The larger micelles produced due to gamma radiation on the emulsion modify the microstructure formation at the edge of the dried drop, thereby alleviating the formation of mechanical stresses that result in the appearance of cracks.

Monolithic polar conjugated microporous polymers: Optimisation of adsorption capacity and permeability trade-off based on process simulation of flue gas separation

The challenge in developing porous materials that significantly reduce energy consumption in industrial gas separation lies in striking a balance between adsorption capacity and permeability. Herein, the precise anchoring of polar oxygen adsorption sites in a robust porous conjugated backbone is achieved through the directed self-assembly of building blocks, resulting in the formation of oxygen-enriched conjugated microporous polymers (O-CMPs). O-CMPs serve as attractive porous hosts for the synergistic separation of CO2 and PM in exhaust gases emitted from point sources. As analyzed by surface electrostatic potential, the introduction of oxygen-doped π-conjugated systems induced surface charge redistribution, enhancing the CO2 quadrupole-dipole effect within a widely distributed microporous network. The O-CMPs exhibited a high CO2 adsorption capacity of 125.84 mg/g at 273 K and 1.0 bar. The monolithic O-CMPs incorporate permanently integrated hierarchical pores with a high micropore ratio. This transport channel can enhance the transfer rate of gas flow while selectively intercepting CO2 and PM. The rigid conjugated molecular chains and hollow nanotube microstructure effectively prevent material densification, yielding a minimal gas permeation resistance of only 5 Pa. Additionally, O-CMPs also demonstrate outstanding stability and PM separation performance under humid and acid/alkaline condition. The visual process simulations serve to further validate that aforementioned design strategy can optimize the trade-off between adsorption capacity and permeability.

Phosphorous Vacancy and Built-In Electric Field Effect of Co-Doped MoP@MXene Heterostructures to Tune Catalytic Activity for Efficient Overall Water Splitting.

Developing cost-effective, durable bifunctional electrocatalysts is crucial but remains challenging due to slow hydrogen/oxygen evolution reaction (HER/OER) kinetics in water electrolysis. Herein, a combined engineering strategy of phosphorous vacancy (Vp) and spontaneous built-in electric field (BIEF) is proposed to design novel highly-conductive Co-doped MoP@MXene heterostructures with phosphorous vacancy (Vp-Co-MoP@MXene). Wherein, Co doping regulates the surface electronic structure and charge re-distribution of MoP, Vp induces more defects and active sites, while BIEF accelerates the interfacial charge transfer rate between Vp-Co-MoP and MXene. Therefore, the synergistic integration of Vp-Co-MoP/MXene efficiently decreases activation energy and kinetic barrier, thus promoting its intrinsically catalytic activity and structural stability. Consequently, the Vp-Co-MoP@MXene catalyst displays low overpotentials of 102.3/196.5 and 265.0/320.0mV at 10/50mA cm-2 for HER and OER, respectively. Notably, two-electrode electrolyzers with the Vp-Co-MoP@MXene bifunctional catalysts to achieve 10/50mA cm-2, only need low-cell voltages of 1.57/1.64V in alkaline media. Besides, experimental and theoretical results confirm that the hetero-structure effectively reduces hydrogen adsorption free energy and rate-determining-step energy barrier of OER intermediates, thereby greatly boosting its intrinsically catalytic activity. This work verifies an effective strategy to fabricate efficient non-precious bifunctional electro-catalysts for water splitting via combination engineering of phosphorous vacancy, cation doping, and BIEF.

Coordinated Adsorption/Desorption Kinetics Enabled by Surface Sulfur Decoration Over Mo2C for Boosted Hydrogen Evolution Reaction

AbstractMaintaining a consistently high current density growth rate in the hydrogen evolution reaction is highly challenging because the limited mass transfer rate at the electrode/electrolyte interface will make the adsorption reaction as the rate‐determining step associated with a low hydrogen coverage, exhibiting a Tafel slope >120 mV dec–1. Therefore, maximizing the current density range in which the desorption reaction is the rate‐determining step, can significantly reduce the overpotential. Herein, a surface sulfur decoration strategy is presented to modify the molybdenum carbide electrocatalyst and achieve coordinated adsorption/desorption kinetics, leading to a dominant Volmer–Heyrovsky mechanism across a wide range of current densities. Both experimental and theoretical results validate the surface charge redistribution induced by sulfur decoration, which subtly optimizes the Gibbs free energy of hydrogen adsorption and enhances the in‐plane polarization field. As a result, the as‐obtained surface sulfur‐decorated molybdenum carbide electrocatalyst exhibits coordinated adsorption/desorption kinetics and efficient hydrogen delivery, ultimately surpassing the commercial Pt/C electrocatalyst for high‐efficiency hydrogen evolution.

Work-function-prompted interfacial charge kinetics in hierarchical heterojunction flexible electrode for efficient capacitive deionization

The growing challenge of water scarcity has spurred extensive research into the development of advanced freestanding pseudocapacitive electrode materials. These electrodes, characterized by their controlled morphology, mechanical complexity, and enhanced desalination capabilities, are advancing water treatment technologies. Additionally, electrodes with interfacially influenced heterostructures demonstrate substantial potential to enhance electrochemical kinetics. However, their widespread adoption is hindered by intricate synthesis procedures and the necessity for multiple discrete components. Herein, the report introduces a cohesive approach that utilizes electrospinning and carbonization to create a freestanding, hierarchically porous nitrogen-doped carbon nanofiber network encapsulating FeNi3 alloy (FeNi3@CNFs) for desalination applications. The method enhances the interfacial effect, mitigates volume changes during sodium ion adsorption and desorption, and improves interfacial stability. By capitalizing on structural and compositional advantages, the novel FeNi3@CNFs electrode delivers outstanding electrochemical properties, including a high desalination capacity (46.47 mg g−1 at 1.2 V), rapid desalination rate (0.77 mg g−1 min−1), and enhanced cyclic durability. Computational analysis via Density Functional Theory shows that the work function prompts a surface charge redistribution at the FeNi3@CNFs heterojunction, optimizing the surface electronic structure and reducing the energy barrier for adsorption. The modification significantly boosts the diffusion kinetics of sodium adsorption. The study delineates a comprehensive methodology for fabricating high-performance heterostructured electrode materials that are effective for capacitive deionization.

Biphase Pd Nanosheets with Atomic-Hybrid RhOx/Pd Amorphous Skins Disentangle the Activity-Stability Trade-Off in Oxygen Reduction Reaction.

The activity-stability trade-off relationship of oxygen reduction reaction (ORR) is a tricky issue that strikes the electrocatalyst population and hinders the widespread application of fuel cells. Here neoteric biphase Pd nanosheets that are structured with ultrathin two-dimensional crystalline Pd inner cores and ≈1 nm thin atomic-hybrid RhOx/Pd amorphous skins, named c/a-Pd@PdRh NSs, for disentangling this trade-off dilemma for alkaline ORR are developed. The superthin amorphous skins significantly amplify the quantity of flexibly low-coordinated atoms for electrocatalysis. An in situ selected oxidation of the top-surface Rh dopants creates atomically hybrid RhOx/Pd disorder surfaces. Detailed energy spectra and theoretical simulation confirm that these RhOx/Pd interfaces can arouse a surface charge redistribution, causing significant electron deficiency and lowered d-band center for surface Pd. Meanwhile, anticorrosive Rh/RhOx species can thermodynamically passivate the neighboring Pd atoms from oxidative dissolution. Thanks to these amplified interfacial effects, the biphase c/a-Pd@PdRh NSs simultaneously exhibit a superhigh ORR activity (5.92 A mg-1, 22.8 times that of Pt/C) and an outstanding long-lasting stability after 100k cycles of accelerated durability test, showcasing unprecedented electrocatalysts for breaking the activity-stability trade-off relationship of ORR. This work paves a bran-new strategy for designing high-performance electrocatalysts through creating modulated amorphous skins on low-dimensional nanomaterials.

Spontaneous Wetting Induced by Contact-Electrification at Liquid-Solid Interface.

Wettability significantly influences various surface interactions and applications at the liquid-solid interface. However, the understanding is complicated by the intricate charge exchange occurring through contact electrification (CE) during this process. The understanding of the influence of triboelectric charge on wettability remains challenging, especially due to the complexities involved in concurrently measuring contact angles and interfacial electrical signals. Here, the relationship is investigated between surface charge density and change of contact angle of dielectric films after contact with water droplets. It is observed that the charge exchange when water spared lead to a spontaneous wetting phenomenon, which is termed as the contact electrification induced wetting (CEW). Notably, these results demonstrate a linear dependence between the change of contact angle (CA) of the materials and the density of surface charge on the solid surface. Continuous CEW tests show that not only the static CA but also the dynamics of wetting are influenced by the accumulation charges at the interface. The mechanism behind CEW involves the redistribution of surface charges on a solid surface and polar water molecules within liquid. This interaction results in a decrease in interface energy, leading to a reduction in the CA. Ab initio calculations suggest that the reduction in interface energy may stem from the enhanced surface charge on the substrate, which strengthens the hydrogen bond interaction between water and the substrate. These findings have the potential to advance the understanding of CE and wetting phenomena, with applications in energy harvesting, catalysis, and droplet manipulation at liquid-solid interfaces.

Electronic Modulation in Cu Doped NiCo LDH/NiCo Heterostructure for Highly Efficient Overall Water Splitting.

Layered double hydroxides (LDHs), promising bifunctional electrocatalysts for overall water splitting, are hindered by their poor conductivity and sluggish electrochemical reaction kinetics. Herein, a hierarchical Cu-doped NiCo LDH/NiCo alloy heterostructure with rich oxygen vacancies by electronic modulation is tactfully designed. It extraordinarily effectively drives both the oxygen evolution reaction (151mV@10mAcm-2) and the hydrogen evolution reaction (73mV@10mAcm-2) in an alkaline medium. As bifunctional electrodes for overall water splitting, a low cell voltage of 1.51V at 10mAcm-2 and remarkable long-term stability for 100h are achieved. The experimental and theoretical results reveal that Cu doping and NiCo alloy recombination can improve the conductivity and reaction kinetics of NiCo LDH with surface charge redistribution and reduced Gibbs free energy barriers. This work provides a new inspiration for further design and construction of nonprecious metal-based bifunctional electrocatalysts based on electronic structure modulation strategies.

Incorporation of N-doped biochar into submicron zero-valent iron for efficient peroxydisulfate activation in soil remediation: Performance and mechanism

The development of strategic methods to enhance the catalytic reactivity and electron efficiency of biochar-modified zero-valent iron (BC-ZVI) via mechanochemistry is highly important and desirable for the use of peroxydisulfate-based advanced oxidation processes (PDS-AOPs) in soil remediation. Herein, novel amphiphilic ball-milled N-doped biochar-ZVI composites (NBC-ZVIbm) were fabricated to activate PDS for efficient pyrene degradation in soil. The N-doped site- and alloying heterojunction-induced surface charge redistribution, directional electron transfer, and amphiphilicity of NBC-ZVIbm were verified, all of which improved the interactions among NBC-ZVIbm, PDS and pyrene. Specifically, NBC incorporation optimized PDS oxidation and pyrene adsorption on NBC-ZVIbm, forming a reaction center that efficiently accelerated the reaction. As a result, 95.5 % of 98.3 mg/kg pyrene in soil was degraded by NBC-ZVIbm/PDS within 7 d, which was 2.3 and 1.5 times greater than that of ball-milled ZVI and BC-ZVIbm, respectively; additionally, the electron efficiency of this process increased to 85.2 %. Characterization of the reaction process suggested that NBC incorporation induced directional electron transfer from ZVI to NBC for PDS activation and SO4•- generation. Subsequently, the amphiphilicity of NBC-ZVIbm promoted soil phase-pyrene desorption and migration, thereby increasing pyrene degradation. This NBC-incorporation method provides a strategy for constructing highly efficient ZVI-based catalysts for the use of PDS-AOPs in soil remediation.

CoF2 coupled MXene with facile active phase reconstruction for oxygen evolution reaction.

The combined CoF2/MXene system was effective in the facile cobalt active species formation induced by surface reconstruction and charge redistribution to promote oxygen evolution reaction.

Incorporation of N-doped biochar into zero-valent iron for efficient reductive degradation of neonicotinoids: mechanism and performance

The extensive use of neonicotinoids on food crops for pest management has resulted in substantial environmental contamination. It is imperative to develop an effective remediation material and technique as well as to determine the evolution pathways of products. Here, novel ball-milled nitrogen-doped biochar (NBC)-modified zero-valent iron (ZVI) composites (named MNBC-ZVI) were fabricated and applied to degrading neonicotinoids. Based on the characterization results, NBC incorporation introduced N-doped sites and new allying heterojunctions and achieved surface charge redistribution, rapid electron transfer, and higher hydrophobicity of ZVI particles. As a result, the interaction between ZVI particles and thiamethoxam (a typical neonicotinoid) was improved, and the adsorption–desorption and reductive degradation of thiamethoxam and ·H generation steps were optimized. MNBC-ZVI could rapidly degrade 100% of 10 mg·L−1 thiamethoxam within 360 min, its reduction rate constant was 12.1-fold greater than that of pristine ZVI, and the electron efficiency increased from 29.7% to 57.8%. This improved reactivity and selectivity resulted from increased electron transfer, enhanced hydrophobicity, and reduced accumulation of iron mud. Moreover, the degradation of neonicotinoids occurred mainly via nitrate reduction and dichlorination, and toxicity tests with degradation intermediates revealed that neonicotinoids undergo rapid detoxification. Remarkably, MNBC-ZVI also presented favorable tolerance to various anions, humic acid, wastewater and contaminated soil, as well as high reusability. This work offers an efficient and economic biochar-ZVI remediation technology for the rapid degradation and detoxification of neonicotinoids, significantly contributes to knowledge on the relevant removal mechanism and further advances the synthesis of highly reactive and environmentally friendly materials.Graphical

Nitrogen modification enhances conductivity and reactivity of sulfidated zero-valent iron: Mechanism and Cr(VI) removal

The incorporation of electronegative elemental nitrogen into zero-valent iron (ZVI)/sulfidated zero-valent iron (S-ZVI) has emerged as an outstanding and promising way to improve decontamination performance. However, the impact of nitrogen modification on the electrical structure of ZVI/S-ZVI remains unclear. Herein, nitrogen-modified sulfidated zero-valent iron (S-N-ZVI) was successfully obtained utilizing cheap and accessible ammonium chloride as the nitrogen source. Raman spectra, FTIR, and density functional theory (DFT) calculations demonstrated that NH3 acts as the dominant nitrogen species. According to the projected density of states and charge-density difference calculations, N is successfully bound to Fe, resulting in a redistribution of surface charge and an increase in electron density of S-N-ZVI, which is reflected in the improved conductivity of S-N-ZVI. Compared with S-ZVI, S-N-ZVI demonstrates better performance in terms of Cr(VI) removal kinetics (kobs improved by 2.075 folds), resistance to air aging, reusability and ability to preserve FeSX stability. This study highlights that the electronic structure significantly impacts the physicochemical properties of S-ZVI and reveals the mechanism of nitrogen modification on the electronic structure of S-ZVI.

Interfacial charge redistribution to promote the catalytic activity of Vs-CoP-CoS2/C n-n heterojunction for oxygen evolution

Modulating surface charge redistribution based on interface and defect engineering has been considered as a resultful means to boost electrocatalytic activity. However, the mechanism of synergistic regulation of heterojunction and vacancy defects remains unclear. Herein, a Vs-CoP-CoS2/C n-n heterojunction with sulfur vacancies is successfully constructed, which manifests superior electrocatalytic activity for oxygen evolution, as demonstrated by a low overpotential of 170 mV to reach 10 mA/cm2. The experimental results and density functional theory calculations testify that the outstanding OER performance of Vs-CoP-CoS2/C heterojunction is owed to the synergistic effect of sulfur vacancies and built-in electric field at n-n heterogeneous interface, which accelerates the electron transfer, induces the charge redistribution, and regulates the adsorption energy of active intermediates during the reaction. This study affords a promising means to regulate the electrocatalytic performance by the construction of heterogeneous interfaces and defects, and in-depth explores the synergistic mechanisms of n-n heterojunction and vacancies.

Flexible ultrathin Nitrogen-Doped carbon mediates the surface charge redistribution of a hierarchical tin disulfide nanoflake electrode for efficient capacitive deionization

Constructing pseudocapacitive electrodes with high specific capacities is indispensable for increasing the large-scale application of capacitive deionization (CDI). However, the insufficient CDI rate and cycling performance of pseudocapacitive-based electrodes have led to a decline in their use due to the corresponding volumetric expansion and contraction that occurs during long-term CDI processes. Herein, hierarchical porous SnS2 nanoflakes are encapsulated inside an N-doped carbon (NC) matrix to achieve efficient CDI. Benefiting from the synergistic properties of the pseudocapacitive SnS2 nanoflakes and few-layered N-doped carbon, the heterogeneous interface simultaneously provides more available vigorous sites and demonstrates rapid charge-transfer kinetics, resulting in a superior desalination capability (49.86 mg g−1 at 1.2 V), rapid desalination rate (1.66 mg g−1 min−1) and better cyclic stability. Computational research reveals a work function-induced surface charge redistribution of the SnS2@NC heterojunction, which can lead to an auspicious surface electronic structure that reduces the adsorption energy to improve the diffusion kinetics toward sodium adsorption. This work contributes to providing a thoughtful understanding of the interface engineering between transition metal dichalcogenides and NC to construct high-performance CDI electrode materials for further industrialization.

Fabrication of highly dispersed Pd-Mn3O4 catalyst for efficient catalytic propane total oxidation

Adjusting the interaction between dual active components for enhancing volatile organic compounds (VOCs) degradation is an effective but still challenging means of air pollution control. Herein, a limited pyrolysis oxidation strategy was adopted to prepare Pd-Mn3O4 spinel catalysts with uniform morphology and active component dispersion. Among these, 1.08Pd-Mn3O4 presented the highest catalytic efficiency with a T90 value of 240 °C, which was 94 °C lower than that of Mn3O4. Characterization and density functional theory (DFT) calculation results revealed that the strong metal-support interaction (SMSI) effect between Pd and Mn3O4 promoted the redistribution of surface charges, thus strengthening the oxidation-reduction ability of the active sites. Moreover, the SMSI effect led to a better migration of surface oxygen species, and boosted the generation of active surface oxygen species. Simultaneously, the Pd catalyst further reduced the energy barrier in the initial stage of the dehydrogenation of propane. Overall, this study provided a novel design strategy for dual active components catalysts with SMSI effect and extended the application of these catalysts in the important field of VOCs elimination.

Boosting the photocatalytic CO2 reduction reaction over BiOCl nanosheet via Cu modification

The development of photocatalytic reduction of CO2 is hindered by slow surface reaction kinetics due to the high activation barrier of CO2 and the lack of activation centers in the photocatalyst. To overcome these limitations, this study focuses on enhancing the photocatalytic performance through incorporating Cu atoms into BiOCl. By introducing a minute amount of Cu (0.18 wt%) into BiOCl nanosheets, significant improvements were achieved, with a CO yield of 38.3 µmol g−1 from CO2 reduction, surpassing that of pristine BiOCl by 50%. To explore the surface dynamics of CO2 adsorption, activation and reactions, in situ DRIFTS was employed. Theoretical calculations were further performed to elucidate the role of Cu in the photocatalytic process. The results demonstrate that the incorporation of Cu into BiOCl induces surface charge redistribution, which facilitates efficient trapping of photogenerated electrons and accelerates the separation of photogenerated charge carriers. Furthermore, Cu modification on BiOCl effectively lowers the activation energy barrier by stabilizing the COOH* intermediate, thereby turning the rate-limiting step from COOH* formation to CO* desorption and boosting the CO2 reduction process. This work unveils the atomic-level role of modified Cu in enhancing the CO2 reduction reaction and presents a novel concept for achieving highly efficient photocatalysts.