Carrier Transfer Research Articles

Cu/S Co-anchoring junction boosted the photogenerated carrier separation efficiency in g-C3N5 for enhanced H2 evolution

C3N5 is emerging as an important visible light catalyst because of its narrow band gap, nontoxicity and thermal stability. Herein, sulfur-doped g-C3N5 (SCN) was prepared by copolymerization of thioacetamide (TAA) and 3-amino-1,2,4-triazole (3-AT). Then copper nanoparticles (Cu NPs) were anchored onto the SCN framework, resulting in the formation of Cu/SCN. It was found that the average H2 production rate of SCN and Cu/SCN was 0.76 and 1.34 mmol g−1 h−1, which was much higher than that of C3N5, respectively. Acting as a new active spots, sulfur doping effectively reduces the band gap of g-C3N5, and the formation of S-Cu bonds further creates an efficient electron transport pathway. As a result, Cu/SCN possesses a broader visible light absorption spectrum, stronger reduction capability, and greater efficiency in photo-induced carrier separation and transfer. Therefore, this work introduces a novel strategy for design of high efficiency photocatalytic H2 evolution carbon nitride through non-noble metal and sulfur anchoring junction.

Hot carrier transfer from plasmon decay in Ag20at H-Si(111) surface: real-time TDDFT simulation in Wannier gauge.

Plasmon decay is believed to play an essential role in inducing hot carrier transfer at the interfaces between plasmonic nanoparticles and semiconductor surfaces. In this work, we employ real-time time-dependent density functional theory (RT-TDDFT) simulation in the Wannier gauge to gain quantum-mechanical insights into the nonlinear dynamics of the plasmon decay in the Ag20nanoparticle at a semiconductor surface. The first-principles simulations show that the plasmon decay is more than two times faster when the Ag20nanoparticle is adsorbed on a hydrogen-terminated Si(111) surface, taking place within 100 femtoseconds of the plasmon excitation. Hot carrier transfer across the interface is observed as the plasmon decay takes place, and nearly 30% of holes are generated deep in the valence band of the semiconductor surface. The use of Wannier gauge in RT-TDDFT simulation is particularly convenient for gaining quantum-mechanical insights into non-equilibrium electron dynamics in complex heterogeneous systems.

Reinforcing Photogenerated Carrier Extraction of Environment‐Friendly InP/ZnSeS Quantum Dots for High‐Performing Photoelectrochemical Photodetection and Solar Energy Conversion

AbstractColloidal InP/ZnSeS‐based quantum dots (QDs) are considered promising building blocks for light‐emitting devices due to their environmental friendliness, high quantum yield (QY), and narrow emission. However, the intrinsic type‐I band structure severely hinders potential photoelectrochemical (PEC) applications requiring efficient photoexcited carrier separation and transfer. In this study, the optoelectronic properties of InP/ZnSeS QDs are tailored by introducing Al dopants in the ZnSeS layer, which concurrently passivate the surface defects and act as shallow donor states for suppressed non‐radiative recombination and improved charge extraction efficiency. Consequently, as‐fabricated InP/ZnSeS:Al QDs‐based PEC‐type photodetector exhibited a high detectivity up to 1011 Jones and a remarkable responsivity of 0.66 A W−1 at 600 nm even under self‐powered condition (0V bias). In addition, as‐prepared InP/ZnSeS:Al QDs‐based photoanode can be alternatively used for PEC hydrogen generation, showing an H2 production rate of 73.7 µmol cm−2 h−1 under 1 sun illumination (AM 1.5G, 100 mW cm−2). The results offer a prospective strategy for optimizing eco‐friendly QDs for high‐performance multifunctional light detection/conversion devices.

Modulating Pore Wall Chemistry Empowers Sonodynamic Activity of Two‐Dimensional Covalent Organic Framework Heterojunctions for Pro‐Oxidative Nanotherapy

AbstractCovalent organic frameworks (COFs) have garnered growing interest in the field of biomedicine; however, their application in sonodynamic therapy remains underexplored due to limited understanding of their intrinsic activity and structure–property relationships. Here, we present a pore wall chemistry modulation strategy for empowering sonodynamic activity to two‐dimensional (2D) COF heterojunctions through in situ growth of COFs on bismuth oxycarbonate nanosheets (B NSs). Compared to the negligible sonodynamic effects observed in the pristine B NSs, the 2D heterojunction with vinyl‐decorated COF pore walls demonstrates a 3.6‐fold enhancement in sonocatalytic singlet oxygen generation. This performance also significantly outperforms that of isoreticular COFs functionalized with methoxy or non‐substituted groups. Mechanistic studies reveal that the vinyl groups in the B@COF (BC) heterojunction facilitate the separation and transfer of charge carriers while also enhancing the adsorption of oxygen molecules. Furthermore, peroxymonosulfate (PMS) loading into the porous COFs boosts the therapeutic efficacy of antitumor nanotherapy via sonocatalytic dual oxidative species generation. These findings underscore the critical role of pore wall chemistry in modulating the sonocatalytic properties of COFs, and advance the development of COF‐based sonosensitizers for pro‐oxidative applications.

Efficient UV-Vis-NIR Responsive CO2 Reduction Photocatalyst with Black Pinecone-Shaped Carbon Nitride Loaded with Lanthanum Oxide.

Photothermal catalysis combines the advantages of photocatalysis and thermal activation, which provides a new research angle for CO2 catalytic reduction. In this study, Black carbon nitride with a three-dimensional (3D) pinecone-shaped structure (BPCN) was prepared by a simple solvothermal method using melamine as a precursor without the aid of a template. Lanthanum oxide doping on the BPCN catalysts (BPCN-La) was achieved by ultrasonic impregnation. This unique pinecone-shaped structure consists of self-assembled and interlaced carbon nitride rods (by SEM). The lanthanum element was distributed on the surface of the CN framework in the form of La2O3 (by XPS). The chemical structures of the samples were characterized by solid-state 13C nuclear magnetic resonance (13C NMR) and elaborated by density functional theory (DFT) analysis. This black carbon nitride expanded the light absorption band edge into the near-infrared (NIR) (300-1400 nm, by UV-vis absorption spectra) and had excellent photothermal conversion activity. La atom doping can significantly boost photogenerated electron excitation (by photocurrent test) and promote carrier separation and transfer (by PL). Upon incorporation of La atoms into BPCN, the highest occupied molecular orbital (HOMO) orbital is more concentrated on the oxygen atoms of La2O3. BPCN-La considerably narrowed the band gap width, exhibited an exceptional photothermal effect, and provided a large surface area, which significantly enhanced the photocatalytic reduction of CO2 reactions. The yields of CO reached 58.2 and 104.9 μmol·h-1·g-1 for BPCN and BPCN-La, respectively, with GCN as the control (6.3 μmol·h-1·g-1). Theoretical reaction pathways and selectivity for the photoreduction of CO2 on BPCN and BPCN-La were studied by DFT simulation. This work provides a new vision for the design of photothermal synergistic without extra-thermal input and full spectral response photocatalysts with high efficiency.

Fabrication and Mechanism Insight of Multidimensional Coupled Metal-Free van der Waals Heterostructures for Enhanced Photocatalytic Hydrogen Evolution.

It is an arduous issue to significantly improve the charge separation efficiency of polymer photocatalysts due to their inherently high exciton binding energy. Herein, based on an interfacial coupling and atom diffusion strategy, a metal-free 3D/2D van der Waals (VdW) heterojunction is fabricated through the modification of rich-vacancy wrinkle-like S8 (Vs-S8) microspheres on the surface of S-doped polymeric carbon nitride (S-PCN) nanosheets. The insight into the mechanism reveals that the interfacial coupling effect induces a strong built-in electric field from S-PCN to Vs-S8, and the carrier transfer behavior abides by the type-II charge transfer pathway, thereby dramatically improving the separation efficiency and transport kinetics of photogenerated carriers. As a result, the as-prepared metal-free 3D/2D Vs-S8/S-PCN VdW heterojunction is endowed with more superior photocatalytic hydrogen evolution (PHE) performance than PCN. The highest average PHE rate is about 11.3 times higher than that of PCN, and the apparent quantum efficiency reaches 30.1% at 400 nm on the optimal 3%-Vs-S8/S-PCN sample. This work contributes a new design strategy for a metal-free VdW heterojunction and provides a feasible avenue for improving the carrier separation efficiency of polymer photocatalysts.

Excitonic Effects on the Ultrafast Nonlinear Optical Response of MoS2 and Fluorinated Graphene/MoS2 Heterostructure Films for Photonic Applications.

In the present work, the ultrafast nonlinear optical (NLO) response of some molybdenum disulfide (MoS2), fluorinated graphene (FG), and FG/MoS2 heterostructure thin films was studied using the Z-scan and optical Kerr effect techniques employing femtosecond laser pulses at different excitation wavelengths (i.e., 400, 570, 610, 660, 800, and 1200 nm). The experiments have shown that the NLO response of the MoS2 and MoS2/FG films was significantly enhanced when the films were excited with 400, 610, and 660 nm laser pulses due to resonance effects with the close-lying excitons in these nanostructures. For a better evaluation of the resonant enhancement of the NLO response, measurements were also carried out at off-resonant wavelengths, i.e., at 570, 800, and 1200 nm. The presence of excitons in the MoS2 and MoS2/FG films resulted in strong saturable absorption and self-defocusing, with exceptionally large values of third-order susceptibilities χ(3) ranging from 10-12 to 10-13 esu. In addition, the NLO response of the MoS2/FG heterostructure was found to be stronger than that of the individual MoS2 and FG films, most probably attributed to interlayer carrier transfer. The determined NLO parameters of the studied nanostructures were found to be comparable to, and in some cases exceeded, those of other reported 2D materials known to exhibit a strong NLO response as well. These findings not only advance the fundamental understanding of the contributions of excitons on the NLO response/properties of transition metal dichalcogenide-based ultrathin films but also highlight the importance of excitons for tailoring their NLO response in view of various applications in advanced optoelectronics and photonic devices.

Exploring Ultrafast Carrier Dynamics in Photoelectrochemical Water Splitting Using Transient Absorption Spectroscopy

AbstractHydrogen fuel produced from water splitting using sunlight remains one of the cleanest and most sustainable energy sources. However, photoelectrochemical hydrogen production faces several challenges, including poor sunlight absorption, deficient charge carrier lifetime and transfer rates, and very sluggish kinetics of the water oxidation half‐reaction. To address these challenges, researchers have concentrated on enhancing the efficiency of photoelectrochemical water splitting. A critical factor in this enhancement is a deeper understanding of the fundamental processes involved in photoabsorption and the subsequent oxidation evolution reaction. The advent of ultrafast lasers has enabled the detailed tracking of charge carriers within materials after sunlight absorption, including their separation and migration to the surface for water oxidation. Ultrafast transient absorption spectroscopy is a powerful technique that allows real‐time observation of the behavior of excited states and charge carriers on femtosecond to nanosecond timescales. Recent studies utilizing ultrafast transient absorption spectroscopy are explored to investigate the dynamics of charge carriers in photoelectrochemical water splitting, providing insights into the mechanisms that lead to the design of enhanced photoanodes with improved efficiency.

Exploring the Relationship Between Electrical Characteristics and Changes in Chemical Composition and Structure of OSG Low-K Films Under Thermal Annealing

The influence of annealing temperature on the chemical, structural, and electrophysical properties of porous OSG low-k films containing terminal methyl groups was investigated. The films were deposited via spin coating, followed by drying at 200 °C and annealing at temperatures ranging from 350 °C to 900 °C. In the temperature range of 350–450 °C, thermal degradation of surfactants occurs along with the formation of a silicon-oxygen framework, which is accompanied by an increase in pore radius from 1.2 nm to 1.5 nm. At 600–700 °C, complete destruction of methyl groups occurs, leading to the development of micropores. FTIR spectroscopy reveals that after annealing at 700 °C, the concentration of silanol groups and water reaches its maximum. By 900 °C, open porosity is no longer observed, and the film resembles dense SiO2. JV measurements show that the film annealed at 450 °C exhibits minimal leakage currents, approximately 5 × 10−11 A/cm2 at 700 kV/cm. This can be attributed to the near-complete removal of surfactant residues and non-condensed silanols, along with non-critical thermal degradation of methyl groups. Leakage current models obtained at various annealing temperatures suggest that the predominant charge carrier transfer mechanism is Poole–Frenkel emission.

Triphenylamine-Functionalized Metal Nanoclusters for Efficient and Stable Perovskite Solar Cells.

Reported herein is a ligand engineering strategy to develop photoelectric active metal nanoclusters (NCs) with atomic precision. Triphenylamine (TPA), a typical organic molecule in the photoelectric field, is introduced for the first time to prepare atomically precise metal NCs that prove effective in the fabrication of perovskite solar cells (PSCs). The scalable synthetic prototype, unique electronic strucuture, and atomically precise structure of the cluster ([(AgCu)37(PPh3)8(TPA-C≡C)24]5+) are illustrated in this work. When being employed as a buffer layer in the perovskite/HTL interface of PSCs, significantly enhanced performance is observed. The resultant n-i-p devices achieved a substantial power conversion efficiency as high as 25.1% and long-term stability. The findings offer valuable insights into preparing functionalized metal NCs that play multiple roles in improving the performance of the device: while the inorganic metal core enhances conductivity, the organic TPA shell promotes the "carrier transfer" between the perovskite and HTL layer and prevents the perovskite from corrosion.

Z-Scheme Enabled 1D/2D Nanocomposite of ZnO Nanorods and Functionalized g-C3 N4 Nanosheets for Sustainable Degradation of Terephthalic Acid.

The urgent need to mitigate water pollution and achieve Sustainable Development Goal 14 (SDG 14)-Life below water, necessitates developing efficient and eco-friendly wastewater treatment technologies. This research addresses this challenge by photocatalytic degradation of terephthalic acid, a precursor for PET bottles using environment-friendly and biocompatible photocatalysts. The 1D/2D nanocomposite comprising zinc oxide (ZnO) nanorods and functionalized graphitic carbon nitride (Zn-TG) nanosheets were synthesized and thoroughly characterized. The nanocomposite effectively mitigated the individual drawbacks of Zn-TG agglomeration and the wide band gap of ZnO as confirmed through zeta potential and Tauc's plot studies, respectively. The synthesized nanocomposite achieved ~100 % degradation within 60 minutes, exhibiting superior kinetics (~2.5 times) compared to pristine samples. The enhanced degradation efficiency was elucidated by efficient charge carrier transfer (~5 times faster) and separation (~2 times improved) as confirmed through electrochemical impedance spectroscopy and time-resolved photoluminescence studies. The proposed Z-scheme pathway provides mechanistic insights. This proposed mechanism is supported by extensive electron paramagnetic resonance (EPR) and scavenger studies. The liquid chromatography-mass spectrometry (LC-MS) analysis confirms the formation of less toxic byproducts for ensuring that the wastewater treatment process is efficient and environmentally friendly. This research helps in developing a highly effective and sustainable wastewater treatment technology.

Enhanced Degradation of Norfloxacin Under Visible Light by S-Scheme Fe2O3/g–C3N4 Heterojunctions

S-scheme Fe2O3/g–C3N4 heterojunctions were successfully fabricated by the ultrasonic assistance method to remove norfloxacin (NOR) under visible light irradiation. The synthesized catalysts were well studied through various techniques. The obtained Fe2O3/g–C3N4 heterojunctions exhibited an optimal photocatalytic degradation of 94.7% for NOR, which was 1.67 and 1.28 times higher than using Fe2O3 and g–C3N4 alone, respectively. In addition, the kinetic constant of NOR removal with Fe2O3/g–C3N4 composites was about 0.6631 h−1, and NOR photo-deegradation was still 86.7% after four cycles. The enhanced photocatalytic activity may be mainly attributed to the formation of S-scheme Fe2O3/g–C3N4 heterojunctions with built-in electric fields, which were beneficial to the separation and transfer of photostimulated charge carriers. Furthermore, a possible photo-degradation mechanism of NOR for S-scheme Fe2O3/g–C3N4 heterojunctions is described.

Construction of Dual Electric Field Synergistic and Magnetic Recyclable SnFe2O4/ZnO Photocatalyst.

The recombination of photoinduced carriers hampers the photocatalysis process. Construction of the heterojunction and built-in piezoelectric field boosts the separation of electrons and holes. Herein, a novel magnetic recyclable SnFe2O4(SFO)/ZnO composite with enhanced photocatalytic performance based on the dual electric field synergism was proposed for the first time. This composite apparently alleviates the carrier recombination in SFO and extends the absorption spectrum of ZnO to the full spectrum. Consequently, 20%SFO/ZnO exhibits an excellent efficiency, which is 2.45 times that of ZnO and 4.61 times that of SFO, respectively. The differences in size and morphology between the SFO nanoparticles and the ZnO nanorods provide more contact areas, thus enlarging the deformation and enhancing the piezoelectric effect. The heterojunction and the piezoelectric field work together to modulate the transferring of carriers and elevate the photocatalytic activity. This design offers a plausible avenue for preparing efficient recyclable photocatalysts for application.

Advanced plasmonic few-layered InSe nanosheet heterojunctions for enhanced photoelectrochemical water splitting

The selenide-based Van der Waals heterojunctions show great potential for the next generation of photoelectronic nanodevices. Herein, we construct a 2D photoanode nanocatalyst that consists of ZnSe nanocrystals with exposed active surfaces coupled with few-layered InSe nanosheets decorated by Au nanoparticles. The resultant ZnSe/AuNPs@InSe multi-heterojunction photoanode demonstrates an outstanding photocurrent density of 4.86 mAcm−2 under AM 1.5 G simulated sunlight (100 mWcm−2), which is 8 times greater than that of the pristine InSe photoanode (0.61 mAcm−2). Moreover, the lifetime of photogenerated charge carriers is extended by a factor of 3. This significant enhancement in photoelectrochemical water splitting in the near-infrared region is attributed to the surface plasmonic effect produced by the modification of Au NPs when bulk InSe is exfoliated into multi-layered flakes. The interfacial coupling effects on carrier transfer dynamics, as revealed by impedance spectroscopy assisted with the First-Principal calculations, show that this photoanode significantly minimizes the internal resistance, boosts the charge carrier separation efficiency, and promotes water oxidation.

BCP Buffer Layer Enables Efficient and Stable Dopant-Free P3HT Perovskite Solar Cells.

Poly(3-hexylthiophene) (P3HT) has garnered significant attention as a novel hole transport material (HTM). Principally, its cost-effective synthesis, excellent hole conductivity, and stable film morphology make it one of the most promising HTMs for perovskite solar cells (PSCs). However, the efficiency of PSCs employing P3HT remains less than ideal, primarily due to the mismatch of energy levels and insufficient interface contact between P3HT and the perovskite film. In this work, 2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline (BCP) was inserted into the P3HT/perovskite interface for effectively alleviating the recombination loss. BCP could effectively anchor uncoordinated Pb2+ and establish π-π stacking interactions with P3HT. These interactions not only neutralize flaws to reduce energy depletion but also enhance the configuration of P3HT, aiding in carrier transfer. Consequently, the BCP-modified device achieved an efficiency of 19.27%, which is significantly superior to the control device (12%).

Designing flexible TiO2/SrTiO3/BiOBr recyclable fiber membrane with spatial dual oxidation sites for photocatalytic uranium extraction under visible light

The utilization of nuclear energy generates a substantial volume of wastewater containing uranium, posing a significant threat to both aquatic ecosystems and human health. The current photocatalytic materials utilized for uranium extraction commonly exhibit insufficient redox capabilities, inefficient separation of photogenerated carriers, and challenging recovery. Therefore, recyclable TiO2/SrTiO3/BiOBr (TSB) dual Z-scheme heterojunction fiber membrane materials with dual oxidation sites were successfully synthesized, with advantages of rapid carrier separation and transfer and a broad photo-response range of the dual Z-scheme heterojunctions. Due to the presence of dual oxidation sites, TSB exhibited an exceptional uranium extraction performance, achieving a remarkable 98.9 % extraction rate without the need for sacrificial agents, which was 2.48, 1.79, and 3.34 times of those of ordinary TiO2, SrTiO3, and BiOBr, respectively. The extraction rate of uranium from TSB was 85 % after five cycles. Optical and photoelectric tests revealed that TSB reduced the bandgap width by 0.25 eV compared to that of TiO2, enhanced the fluorescence lifetime by 1.3 ns, lowered the electrical resistance, and higher optical current density, confirming the effective charge transport at the catalyst interfaces. The charge transfer routes in the TSB dual Z-scheme were confirmed by X-ray photoelectron spectroscopy and density functional theory. The potent oxidizing ·OH generated by TSB played a crucial role in facilitating the conversion of U(VI) into insoluble (UO2)O2·2H2O. In conclusion, this work provides a novel strategy for the design of dual Z-scheme heterojunctions and offers a new method for practical and recoverable uranium extraction.

Photothermal-assisted S-scheme heterojunction of NiPS3 nanosheets modified ZnIn2S4 microspheres for promoting photocatalytic hydrogen evolution

Exploring high-efficiency photocatalysts for solar hydrogen (H2) generation through water splitting is of great significance for addressing both energy shortage and environmental contamination. In this work, a facile self-assembly strategy was developed to couple NiPS3 nanosheets (NPS NSs) with ZnIn2S4 (ZIS) microspheres to synthesize NPS NSs/ZIS (NPS/ZIS) composites, featuring a characteristic of S-scheme charge transfer mechanism. The NPS/ZIS composites possess broad-spectrum light absorption property, improved photothermal effect and efficient charge transfer, showcasing exceptional solar-to-chemical energy conversion capability for visible-light-driven photocatalytic hydrogen evolution (PHE). The photothermal effect derived from NPS NSs loading can facilitate charge carrier transfer across the interfaces and surface reaction kinetics. By carefully adjusting the mass ratio of NPS NSs, the optimized 4-NPS/ZIS exhibits excellent stability and significantly improved PHE activity (1827.6 μmol⋅g−1⋅h−1) in water, which is 18.4 times higher than that of bare ZIS (99.4 μmol⋅g−1⋅h−1). Furthermore, the 4-NPS/ZIS also shows the high PHE efficiency of 312.2 μmol⋅g−1⋅h−1 in seawater. Diverse characterization results reveal that the remarkably enhanced PHE performance primarily arises from the synergistic effect of S-scheme heterostructure, heightened light harvesting capacity, and enhanced photothermal effect. On the basis of density functional theory (DFT) simulations and experimental verifications, a possible PHE mechanism via the S-scheme heterojunction with photothermal assistance in NPS/ZIS is proposed. This study serves as inspiration for the development of novel photothermal-assisted S-scheme photocatalysts, paving the way for efficient and sustainable green energy production.

Strong Metal–Support Interaction Induces Dual Reaction Sites for Ultrasensitive and Stable NO2 Detection in Extreme Environments

AbstractThe tripartite combination of a high density and stability of surface reaction sites, complemented by the longevity and efficient transfer of interface carriers, along with the effective adsorption and activation of target gas molecules, jointly determines the efficiency of chemiresistors. In this work, the strong metal–support interaction (SMSI) of Pt─Ce3+ is formed by the NaBH4 reduction method and thus prepares metal‐dynamically stable PtNR─CeO2 with Pt─Ce3+ and Pt─Pt reaction sites. The formation of SMSI induces the recombination of the chemical structure of the CeO2 surface causing the localization of electron‐rich Ce3+, which greatly increases the charge concentration at the interface. The experimental findings of the strong interaction of Pt─Ce3+ bonding and the catalytic effect of Pt optimized the adsorption mode of PtNR─CeO2 on target gas, which maintains stable catalytic activity at 20–500 °C and achieving a notable detection response value of 1.43 for 20 ppb NO2. This work offers fresh insights into designing stable oxide chemiresistors with efficiency and stability by customizing reaction sites at the atomic level.

MgAc2-Modified SnO2 Electron Transport Layer for Highly Efficient and Thermal Stable Perovskite Solar Cells.

There are always defects and oxygen vacancies in SnO2 prepared by solution methods, hindering efficient carrier transfer between SnO2 and the perovskite in perovskite solar cells. Thus, we employed MgAc2 to modify the interface. Carboxyl groups of MgAc2 filled the oxygen vacancies in SnO2, reducing its surface defect density, and Mg2+ partially replaced surface Sn4+, improving the properties of the SnO2 layer. Finally, perovskite solar cells modified with MgAc2 exhibited a significant improvement in open-circuit voltage and fill factor, improving the power conversion efficiency from 20.52% to 22.02%. Moreover, MgAc2-devices maintained 80% of the initial efficiency after 1250 h in thermal stability tests at 85 °C and 30% relative humidity compared to control devices. This work provides a method for treating the SnO2 electron transport layer and demonstrates the synergistic effects of Mg2+ and acetate ions, which can facilitate the development of efficient and stable perovskite solar cells.

Anchoring Ag Atom on Carbon Vacancy Enriched Carbon Nitride to Synergistically Promote CO2 Photoredution with Water

AbstractPristine carbon nitride (CN) has low CO2 reduction ability due to its sluggish charge carriers transfer and CO2 activation. Herein, carbon vacancy (CV) and Ag single atoms (SAs) with N2 coordination are simultaneously introduced into CN with the ordered structure for stable and efficient photoreduction of CO2 in the presence of H2O. The optimal sample loaded with 0.053 wt.% Ag evolve 173.0 µmol g−1 CO in 3 h with 89% selectivity, which is 11.7 times higher than that of pristine CN (14.7 µmol g−1). Experiments and theoretical calculations reveal that the CV and Ag–N2 sites promote CO2 adsorption/activation and the generation of *COOH and *CO. KSCN‐assisted calcination induces more ordered arrangement of melon chains, which can accelerate charge transfer/separation and facilitate H2O oxidation, thus accounting for the largely improved CO2 photoreduction performance. This study adopts a new method to prepare Ag SA‐anchored and C‐deficient CN, and provides insights into their synergistic roles in enhancing CO2 reduction.