Defect Engineering Strategies Research Articles

Oxygen vacancy mediated photocatalysis of Ti3C2 MXene quantum dots/W18O49 hybrid membrane for peroxymonosulfate-enhanced oxidation degradation

Photocatalytic membrane technology shows great prospects in water decontamination. Coupling photocatalysis with peroxymonosulfate (PMS) can boost oxidation capacity by combining their superiorities sufficiently. Herein, 0D Ti3C2 MXene quantum dots (TMQDs) embedded oxygen vacancy-rich 3D sea urchin-like W18O49 microspheres (OTW) were synthesized via facile interface engineering combined with green plasma etching strategy. The visible-light driving flow-through membrane reactor was capable of degrading cyclophosphamide, a typical anticancer drug, and other common pollutants (5-fluorouracil, carbamazepine, bisphenol A, rhodamine B), with the removal and mineralization efficiencies of 10 μM pollutants reaching over 99 % and 63 %−79 % in 60 min with 0.5 mM PMS. Moreover, the long-term reliability of OTW membrane was validated through continuous treatment of 20 L sewage. Significantly, the newly designed photocatalytic membrane exhibited good tolerance to wide pH ranges, common coexisting substances in water, and various actual water matrix. The results of experimental and DFT theoretical calculations revealed that Schottky junction formed on the TMQDs/W18O49 interfaces and tunable O-defects could optimize electronic configuration, improve solar energy utilization, prevent photogenerated carriers’ recombination, promote H2O and PMS dissociation, making it possible that more •OH and SO4•− radicals participated in the oxidation degradation reaction. This study offers a design idea for preparing efficient and robust photocatalytic membrane via interface engineering and defect engineering strategies, which might contribute to bridging the translational gap between emerging photocatalytic techniques and practical environmental applications in near future.

Green-assisted synthesis of highly defective nanostructured Fe-doped SnO2: Magnetic and photocatalytic properties evaluation

Here we present a comprehensive characterization of the properties of undoped and Fe-doped SnO2 nanoparticles prepared with Syzygium cumini leaves extract. The phytochemicals present in the leaves extract act as cation chelating and capping of the nanoparticles. It is observed a relative high concentration of tin (up to 10 %) and oxygen (up to 5%) vacancies promoted by surface adsorbed OH− and by Fe-doping, respectively. The magnetic characterization reveals a ferromagnetic with a saturation monetization up to 20×10−3 emu/g for the higher defective and Fe-doped sample. This behavior associated mainly to tin vacancies for the undoped samples, and to the formation of bound magnetic polarons between the incorporated Fe and the oxygen vacancies for the doped samples. Oxygen vacancies and incorporated Fe improve the SnO2 photocatalytic efficiency in the visible range of the electromagnetic spectrum by decreasing the SnO2 effective bandgap from 3.6 eV for the undoped SnO2 sample to only 1.9 eV for the Fe-doped SnO2 sample, and by acting as electron-trapping centers increasing the system quantum efficiency. Due to the ferromagnetic behavior of the studied samples, it was also considered the effect of spin-dependent processes in the observed photocatalytic improvement. Our results highlight the key role of defect engineering strategies to optimize the physical and chemical properties of semiconductor oxides for application in the development of spintronic and quantum information devices, and in systems devoted to wastewater purification through advanced oxidation processes.

Synergistic Mo and W single atoms co-doped surface hydroxylated NiFe oxide as bifunctional electrocatalysts for overall water splitting

Two novel defect engineering strategies, surface hydroxylation and single atom (SA) doping, are explored to fabricate a high performance bifunctional water electrolysis catalyst, synergistic Mo and W SAs co-doped surface hydroxylated NiFe oxide (FN-MoWact). The product catalyst achieves ultralow overpotentials of 196 and 246 mV for oxygen evolution reaction (OER) and decent overpotentials of 79 and 246 mV for hydrogen evolution reaction (HER) at current densities of 10 and 500 mA cm−2, respectively. For overall water splitting, the FN-MoWact//FN-MoWact couple requires ultralow cell voltages of 1.504 and 1.729 V to deliver current densities of 10 and 500 mA cm−2, respectively, and remains stable after a 100-hour operation at an initial current density of 534 mA cm−2. The enhanced electrocatalytic activities are attributed to surface hydroxylation and doping of synergistic Mo and W SAs. The two defect engineering modifications, as supported by analyses of density functional theory calculations and in-situ X-ray absorption spectroscopy, lead to a proper reduction in metal-oxygen covalency, thus minimizing the energy difference of the rate-determining step of the OER process, and create surface active sites with a d-band center located closer to the Fermi level, thus properly strengthening proton binding to enhance HER activities.

Vanadium‐Based Cathodes Modification via Defect Engineering: Strategies to Support the Leap from Lab to Commercialization of Aqueous Zinc‐Ion Batteries

AbstractIn advancing aqueous zinc‐ion batteries (AZIBs) toward commercial viability, vanadium (V)‐based cathodes are pivotal, offering broad redox ranges, and compatibility with water's electrochemical limits. Despite their great potentials, V‐based cathodes face challenges in transitioning from lab to commercialization. Defect engineering is exploited as a pivotal technique that endows the cathodes with unexpected physical and chemical properties to break the intrinsic bottleneck and, in turn, enhance their electrochemical performances. This review delves into the role of defect engineering on V‐based materials, underscoring its potential in mitigating the critical challenges. It starts by encapsulating the current characteristics of V‐based cathodes in AZIBs. Research efforts related to various defects, such as oxygen vacancies, cation vacancies, cationic doping, anionic doping, water intercalation, and lattice disorders/amorphization, are then rationalized and discussed. The fabrication and characterization techniques of defect engineering are also summarized. By integrating the conclusions from existing works and tailoring defect engineering strategies, a few perspectives are provided for systematically employing defect engineering to pave the way for a more efficient transition of these promising materials from laboratory breakthroughs to commercially viable energy storage solutions.

Au-Cu dual-single-atom sites on Bi2WO6 with oxygen vacancy for CO2 photoreduction towards multicarbon products

CO2 photoreduction into high-value-added C2+ products struggles with energetic challenges in forming critical intermediates and multiple C−C bonds. Herein, an effectively synthesized photocatalyst, Bi2WO6 nanosheets with oxygen vacancies anchoring Au and Cu dual single atoms on the surface, can convert CO2 and H2O vapour into C3H6 and C2H4. The high product selectivity of 18.2 % for C3H6 and 65.4 % for total C2+ hydrocarbons are achieved under concentrated light irradiation (2.4 W·cm−2). Au-Cu dual-single-atom sites and defect engineering strategies exhibit synergistic effects on optimizing the reaction thermodynamics and charge kinetics for CO2 conversion. Theoretical calculations provide reference values for reaction pathways of C3H6 and C2H4 formation, with the C−C couplings being potential determining steps of multicarbon product formation. Our work offers a promising strategy with a combination of concentrated light irradiation technology and catalyst modification to achieve high selectivity of C2+ products.

Removal of radioactive iodine by Cu2O prepared with PVP as an active agent: Role of crystal facets and oxygen vacancy in adsorption mechanisms

Radioactive iodine removal continues to pose significant challenges. In this study, the advantages of crystal facet and defect engineering were utilized to synthesize six types of Cu2O nanocrystals with varying crystal facet exposed, crystal edge exposed, and abundant oxygen vacancies (OVs). Compared to pure {100} and {111} exposed Cu2O, {100}+{111} co-exposed Cu2O exhibited superior adsorption capacity and adsorption rate for iodide ions (I−), achieving a removal efficiency of 96 % for trace I− (0.1 mg/L). Moreover, OVs significantly contribute to iodide ion (I−) adsorption. Experimental and density functional theory (DFT) analyses confirmed that the active sites on {100}/{111} crystal edges possess the highest affinity for I−. The OVs disrupts the charge balance of the Cu2O surface and increases unsaturated coordination sites of Cu, therefore, it significantly enhanced the affinity for I−. This research offers insights into the design of effective I− adsorption materials using crystal facet and defect engineering strategies.

Lattice-dislocated bismuth nanowires formed by in-situ chemical etching on copper foam for enhanced electrocatalytic CO2 reduction

Electrochemical CO2 reduction reaction (CO2RR) to HCOOH is one of the most feasible and economical methods to achieve carbon neutrality. Bismuth (Bi), as a metal catalyst for CO2RR, is considered to have great potential for application and has been widely studied due to its high formate selectivity, low toxicity, cheapness, and abundance. Unfortunately, low current density and short electrode lifetime have hindered its progress towards practical applications. In this work, we present a method that enables the chemical etching of Bi on Cu, which is capable of spontaneously accomplishing the loading of Bi on Cu foam in the liquid phase at room temperature. Additionally, to provide more abundant catalytically active sites, twisted Bi nanowires (BiNWs) with lattice dislocations were successfully prepared on the surface of Cu foam using a three-step chemical method involving oxidation, reduction, and in-situ etching. The Cu Foam@BiNWs was found to be a highly active electrocatalyst for CO2 reduction to formate at a low applied potential, achieving a faradaic efficiency for formate (FEFormate) of 95 % and a formate partial current density of ∼ 12 mA cm−2 at −0.78 V vs. RHE (reversible hydrogen electrode). Even within such a wide potential window of −0.68 ∼ -1.08 V vs. RHE, the FEFormate is consistently above 90 %. Such exceptional CO2 reduction activity can be attributed to the distortions and lattice dislocations present in the surface BiNWs. Furthermore, the Cu Foam@BiNWs electrode demonstrated a total current density close to 100 mA cm−2 at −0.98 V in an alkaline flow cell, while maintaining excellent catalytic stability over a prolonged 30-hour period of high current density electrochemical activity, thus showing potential for advancing the industrialisation of formate production. This work emphasizes the crucial role of size-dependent catalysis and crystal defect engineering strategies in the field of electrocatalysis, elucidates the mechanism of the rate-determining step (RDS) in the electrocatalytic CO2 reduction process on the developed catalysts, which can provide valuable insights into the design and development of high performance electrocatalysts not only in CO2RR but also in other fields.

Manipulating CNT Films with Atomic Precision for Absorption Effectiveness–Enhanced Electromagnetic Interference Shielding and Adaptive Infrared Camouflage

AbstractPromoting advanced functional films that integrate protective behaviors for synergetic radar, infrared (IR), and visible light is confronted with extreme challenges. The effective integration of shielding capacity and IR camouflage into single‐component carbon films remains an enormous challenge because of limited conductivity and high IR absorption. In this work, carbon nanotube (CNT) films with excellent electromagnetic interference (EMI) shielding, switchable IR camouflage, and energy conversion are obtained via a (FCCVD) method and subsequent defect engineering strategies induced by temperature (Strategy I) and N/S co‐doping (Strategy II). Wherein the effect on the electronic configuration as well as multi‐spectra performance is deeply explored. Ascribing to the synergistic effects of strategies, defective CNT films present superior EMI shielding effectiveness (SE) with a high absorption effectiveness ratio of 86.9%, and a large span of emissivity (0.479), which provides the necessary condition for various application scenarios. Under the applied electric field excitation, the IR radiation of CNT films can adapt to rapidly changing surroundings, such as low‐high/high‐low temperatures. Besides, the desirable energy conversion performance and de‐icing can be achieved. This work supplies a feasible strategy for designing EM absorption, adaptive IR camouflage, and energy conversion to confront multiband surveillance.

PH-Tuned Enantioselectivity Reversal in a Defective Chiral Metal Organic Framework.

The introduction of chirality into easy-scalable metal-organic frameworks (MOFs) gives rise to the development of advanced electrochemical sensors. However, integrating chirality by directly connecting metal ions and chiral ligands is unpredictable. Postmodification synthesis is a common method for synthesizing chiral MOFs, but it reduces the size of chiral channels and poses obstacles to the approach of chiral guest molecules. In this work, missing connection defects were introduced into the chiral MOFs through defect engineering strategies, which enhance the recognition of the target enantiomers. pH can tune enantioselectivity reversal in defective chiral MOFs. The chiral MOFs show enantioselectivity for d-Trp at pH = 5 and l-Trp at pH = 8. From the results of zeta potential, regardless of pH 5 or 8, the chiral MOF has a positive potential. The chiral MOFs are positively charged, while tryptophan is negatively charged when pH = 8. The difference in the positive and negative charge interactions between the two amino acids and chiral MOFs leads to chiral recognition. However, the difference in π-π interaction between chiral MOF and Trp enantiomers mainly drives chiral recognition under pH = 5. This study paves a pathway for the synthesis of defective chiral MOFs and highlights the pH-tuned enantioselectivity reversal.

Defect and interface/surface engineering synergistically modulated electron transfer and nonlinear absorption properties in MoX2 (X = Se, S, Te)@ZnO heterojunction.

Systematic interface and defect engineering strategies have been demonstrated to be an effective way to modulate the electron transfer and nonlinear absorption properties in semiconductor heterojunctions. However, the role played by defects and interfacial strain in electron transfer at the interface of the MoX2 (X = Se, S, Te)@ZnO heterojunction remains poorly understood. Herein, using the MoX2@ZnO heterojunction, we reveal that vacancies play a critical role in the interfacial electron transfer of heterojunctions. Specifically, we present the defect and interface engineering of the MoX2@ZnO heterojunction for controlled charge transfer and electron excitation-relaxation. The experimental characterization combined with first-principles calculations showed that the presence of defects promoted the transport of photogenerated carriers at the heterojunction interface, thereby inhibiting their rapid recombination. The DFT calculation confirmed that the electron band structure, density of states and charge density distribution in the system changed after the formation of Mo-O bonds. On the basis of defects and interfacial stress and the effective charge transfer, the MoX2@ZnO heterojunction exhibited excellent excitation and emission behaviors. The nonlinear optical regulation behavior of TMDs is expected to be realized with the help of the defects and interface/surface synergistically modulated effect of ZnO nanoparticles. The local strain generation on the MoX2@ZnO heterojunction boundary provides a new method for the design of new heterogeneous materials and will be of great significance to investigate the contact physical behavior and application of metals and two-dimensional (2D) semiconductors. This work provides some inspiration for the construction of heterojunctions with rich defects and surface/interface charge transfer channels to promote tunable electron transfer dynamics, thereby achieving a good nonlinear optical conversion efficiency and efficient charge separation in optoelectronic functional materials.

Intercalation and defect engineering of layered MnPS3 for greatly enhanced capacity and stability in sodium-ion batteries

Two-dimensional ternary metal phosphorus trisulfides have emerged as promising anode materials for sodium-ion batteries owing to their intriguing layered structure, flexible composition and high surface activity. However, these materials still suffer from low rate capability and poor cycling performance due to pulverization during the de/sodiation processes. Herein, two-dimensional intercalated Mn1−xPS3(Me4N+)2x with vacancy defects and expanded interlamellar spacing is prepared through a mild liquid-phase reaction using MnPS3 powder grown by chemical vapor deposition as the precursor. The vacancy defect regulates the electronic structure and improves the electrical conductivity, while the expanded interlayer space accelerates ion diffusion, providing spacious storage space for Na+ ions and alleviating volume expansion. These synergistic effects collectively enhance the capacity and stability of MnPS3. The prepared Mn1−xPS3(Me4N+)2x electrode affords high capacities of 890 mAh/g at 0.1 A/g and 615 mAh/g at 5 A/g, along with an ultralong cycle life of 700 cycles at 1 A/g with a capacity retention of 94 %. These results hold significant implications in advancing the electrochemical performance of MPS3-based sodium-ion batteries by employing intercalation and defect engineering strategies.

Topotactically transformable antiphase boundaries with enhanced ionic conductivity

Engineering lattice defects have emerged as a promising approach to effectively modulate the functionality of devices. Particularly, antiphase boundaries (APBs) as planar defects have been considered major obstacles to optimizing the ionic conductivity of mixed ionic-electronic conductors (MIECs) in solid oxide fuel applications. Here our study identifies topotactically transformable APBs (tt-APBs) at the atomic level and demonstrates that they exhibit higher ionic conductivity at elevated temperatures as compared to perfect domains. In-situ observation at the atomic scale tracks dynamic oxygen migration across these tt-APBs, where the abundant interstitial sites between tetrahedrons facilitate the ionic migration. Furthermore, annealing in an oxidized atmosphere can lead to the formation of interstitial oxygen at these APBs. These pieces of evidence clearly clarify that the tt-APBs can contribute to oxygen conductivity as anion diffusion channels, while the topotactically non-transformable APBs cannot. The topotactic transformability opens the way of defect engineering strategies for improving ionic transportation in MIECs.

Recent Advances on Transition Metal Chalcogenide for Sodium-Ion Batteries

Sodium-ion batteries (SIBs) are expected to replace lithium-ion batteries (LIBs) as a new generation of energy storage devices due to their abundant sodium reserves and low cost. Among the anode materials of SIBs, transition metal chalcogenides (TMXs) have attracted much attention because of their large layer spacing, narrow band gap, and high theoretical capacity. However, in practical applications, TMXs face problems, such as structural instability and poor electrical conductivity. In this review, the research progress and challenges of TMXs in SIBs in recent years are summarized, the application of nanostructure design, defect engineering, cladding engineering, and heterogeneous construction techniques and strategies in improving the electrochemical performance of TMXs anode are emphatically introduced, and the storage mechanism of sodium is briefly summarized. Finally, the application and development prospects of TMX anodes in electrochemical energy storage are discussed and prospected.

Defective Photocathode: Fundamentals, Construction, and Catalytic Energy Conversion

AbstractThe development of a long‐term and sustainable energy economy is one of the most significant technological challenges facing humanity. Photoelectrochemical (PEC) technology is considered as the most attractive route for converting solar energy into chemical energy. However, the slow reaction kinetics of PEC oxidation and reduction greatly hinder its practical application. To address this issue, engineering photoelectrodes with various defects can significantly improve their catalytic performance, which can not only regulate catalyst electronic structure but also promote charge transfer/separation by serving as an active/adsorption/energy storage site. Herein, the defect engineering strategies for photoelectrodes are systematically summarized, focusing on the latest progress in defective photocathode for energy conversion. First, an overview of defect types, basic principles of photocathode, and the positive role of defects in the photocathode are provided. Second, the construction strategies and characterization methods of defective photocathode are summarized. Then, the progress of typical energy conversion applications, including hydrogen production, CO2 reduction, and nitrogen reduction over defective photocathode, is reviewed, highlighting the crucial role of defects in high catalytic performance. Finally, the challenges and future prospects of defective photocathode are discussed, aiming to bring new opportunities for the development of photocathode through defect engineering.

Extraordinary photooxidation properties of ZnO nanosheets with surface oxygen vacancies of low density

Surface defect engineering strategies are critical for catalytic activity, especially in the photodegradation of organic pollutants. However, the exact function of the oxygen vacancies for the photooxidation performance of ZnO is unclear. Oxygen vacancies might act as electron donors to encourage carrier separation and then boost catalytic efficiency; besides, excessive oxygen vacancies might act as recombination centers for photogenerated electron–hole, which impairs photocatalytic performance. Therefore, the specific effect of the amount of oxygen vacancies in ZnO needs to be investigated. We developed a facile method, which is inspired by the aforementioned strategy, to adjust the amount of oxygen vacancies in ZnO nanosheets for exploring its photocatalytic activity. ZnO nanosheets with oxygen vacancies of low density exhibit a greatly enhanced photooxidation ability and can rapidly and stably degrade high concentration (4 × 10−4 mol/L) of phenol compared with nearly inactivity of the ZnO nanosheets with plentiful oxygen vacancies. This mechanism of the improved photocatalytic activity is proposed to be mainly due to the significant reduction in oxygen vacancies as carrier recombination centers and the increase in photogenerated electron–hole mobility. This research presents a new idea for the surface defect engineering design of regulated photocatalysts to enhance photocatalytic activity.

Crystal-Phase-Change-Induced Formation of Defect-Rich Pt–Ag Nanoshells for Efficient Electrooxidation of Formic Acid

In recent years, defect engineering has proven to be a powerful approach for enhancing the electrocatalytic performance of nanomaterials. To advance the application of defect-rich nanomaterials, it is critical to develop new defect engineering strategies. In this study, we propose a new strategy for creating an abundance of defects in ultrathin metal nanomaterials by crystal phase engineering. Specifically, we synthesized hexagonal close-packed (hcp)/face-centered cubic (fcc) Ag@Pt core/shell nanoechinus by using hcp/fcc mixed-phase Ag nanoechinus as templates through epitaxial growth. Selective etching of the Ag templates resulted in a transformation of the epitaxial layer from the hcp to the fcc crystal phase, along with the formation of abundant defects in the Pt–Ag nanoshells (Pt–Ag NSs). Subsequently, we employed thermal annealing to produce porous walls in the defect-rich Pt–Ag NSs. Compared to commercial Pt/C, the resulting defect-rich Pt–Ag NSs with ultrathin and porous walls demonstrated superior electrocatalytic performance in formic acid oxidation due to their unique porous, ultrathin, defect-rich, and alloy structures. Our findings highlight a new application of crystal phase engineering for synthesizing defect-rich nanomaterials and may lead to new opportunities for engineering the electrocatalytic properties of metal nanomaterials through defect engineering.

Comparative investigation on defect-engineered Bi2S3-xSex for boosting photocatalytic Cr(VI) reduction and in-situ H2O2 generation: Mechanistic and kinetic studies

Heterogeneous photocatalysis has been demonstrated as a highly effective approach in addressing the difficulties encountered by conventional technologies in environmental remediation. Herein, for the first time, a novel hierarchical photocatalyst of selenium-doped Bi2S3 (Bi2S3-xSex) was successfully synthesized through a one-spot hydrothermal route followed by a vacancy engineering process (V-Bi2S3-xSex). The photocatalytic reduction of Cr(VI) and in-situ generation of hydrogen peroxide (H2O2) under simulated solar-light irradiation were performed to evaluate the catalytic activity of the as-prepared samples. The catalytic activity of as-prepared samples was evaluated toward the photocatalytic reduction of Cr(VI) and in-situ generation of H2O2 under simulated solar-light irradiation. Notably, V-Bi2S3-xSex (V-BSSe-5, as optimum sample) exhibited a photo-reduction of Cr(VI) at a rate of 97.04% during 150 min, which was 1.53- and 1.39-fold higher than those of pure Bi2S3 and Bi2Se3, respectively. Interestingly, the V-Bi2S3-xSex photocatalyst not only harvested more incident light in the UV–vis and near-infrared (NIR) regions but also supplied many active sites, improving the promotion of photo-generated charge-carriers, inhibiting charge recombination, and thus enhancing the photocatalytic activity. In addition, V-BSSe-5 showed greater photocatalytic efficiency for H2O2 generation, which was 15.69, 10.07, and 1.79 times higher than those of Bi2S3, Bi2Se3, and BSSe-5, respectively. The charge-carrier migration pathway and possible photocatalytic mechanisms were systematically discussed by assisting the electron spin resonance and ultraviolet photoelectron spectroscopy analyses. The findings of this study demonstrate that doping and defect engineering strategies have the potential to be a significant advancement in the development of visible- and NIR-light responsiveness photocatalysts, thereby providing a solution to current environmental and energy challenges.

Defects in Carbon-Based Materials for Electrocatalysis: Synthesis, Recognition, and Advances.

ConspectusOwing to climate change and over-reliance on fossil fuels, the study and development of sustainable energy is of essential importance in the next few decades. In recent years, rapid advances have been witnessed in various power to gas electrocatalysis technologies including oxygen reduction reaction (ORR), oxygen evolution reaction (OER), and hydrogen evolution reaction (HER) for realizing the target of blue planet with carbon neutrality. Nevertheless, practical applications with superior performance and affordable cost are largely limited by the electrode materials because the reactions are regularly driven by precious metals such as platinum (Pt) or iridium (Ir) based catalysts. Therefore, it is of significance to develop novel electrocatalysts with high electroactivity and limited cost for boosting the commercialization of green hydrogen technology.Since nitrogen-doped carbon nanotubes were first reported for enhanced ORR performance in 2009, the exploitation of carbon-based metal-free catalysts (CMFCs) as potential replacements for the precious metal electrocatalysts has become an attractive research field. To date, great progress has been made in developing new dopant strategies for CMFCs; however, the details of the catalytic mechanism and identification of active sites remain unclear, owing to the complexity in controlling the dopants and their homogeneity in carbon-based materials. To tackle this issue, our group has presented a series of works on defects catalyzing electrochemical reactions and proposed a defect catalysis mechanism since 2015. This theory is now widely accepted by the research community and has become a very important area in electrocatalysis worldwide.In this Account, we first present the defect theory for the reasonable design of defective carbon-based materials (DCMs) and subsequently summarize our previous works on the state-of-the-art defect engineering strategies to design DCMs possessing high activity, with the particular emphasis on the conjunction between defect structures and electrochemical performances. We also categorize recent defect modulation approaches on active sites in DCMs as well as showcase the advanced characterization techniques to confirm the types and densities of defects in DCMs. Finally, several perspectives on the challenges and future research opportunities of this exciting field are proposed. Remarkably, rapid advances of DCMs possessing both high electrochemical activities and low cost as a new generation of electrode materials may greatly facilitate the deployment of sustainable energy infrastructures.

Photothermal Conversion Boosted Photocatalytic CO2 Reduction over S-Scheme CeO2@Cu-TCPP: In Situ Experiments and DFT Calculations

Herein, interfacial and defect-engineering strategies synergistically promote photocatalytic properties. Because of the matching energy levels and the close interfacial contact, the CeO2@Cu-TCPP S-scheme architecture is successfully constructed via the in situ wet chemistry route. Photothermal conversion assists abundant OVs on the CeO2 compartment. Strong evidence of an S-scheme charge transfer path is verified by density functional theory (DFT) calculations and in situ irradiated X-ray photoelectron spectroscopy (XPS). This S-scheme heterojunction system is more deep-seated in facilitating the separation and transfer of photogenerated carriers as well as acquiring strong photoredox ability. Meanwhile, the abundant OVs proved by XPS and electron paramagnetic resonance spectra (ESR) enhanced the light-harvesting capacity and conductivity and shortened the transfer route. As a result, this synergistic heterojunction could mostly promote photocatalytic CO2 activation. The typical 0.25CeO2@ Cu-NS exhibited the best photocatalytic CO2RR to form CO and CH4 (rate: 229.6 μmol·g–1), which is even 45.8- and 1.5-folds higher than those of pristine LA-CeO2 (5.0 μmol·g–1) and Cu-TCPP (152.2 μmol·g–1), respectively, higher than those of other reported CeO2-based photocatalysts. This study presents a reinforcement and matrix prospect for domain charge behaviors to accelerate CO2 activation.

The Precision Defect Engineering with Nonmetallic Element Refilling Strategy in g-C3 N4 for Enhanced Photocatalytic Hydrogen Production.

Traditional defect engineering and doping strategies are considered effective means for improving H2 evolution, but the uncontrollability of the modification process does not always lead to efficient activity. A defect-induced heteroatom refilling strategy is used here to synthesize heteroatoms introduced carbon nitride by precisely controlling the "introduction" sites on efficient N1 sites. Density functional theory calculations show that the refilling of B, P, and S sites have stronger H2 O adsorption and dissociation capacity than traditional doping, which makes it an optimal H2 production path. The large internal electric field strength of heteroatom-refilled catalysts leads to fast electron transfer and the hydrogen production of the best sample is up to 20.9mmolg-1 h-1 . This work provides a reliable and clear insight into controlled defect engineering of photocatalysts and a universal modification strategy for typical heteroatom and co-catalyst systems for H2 production.