Tunable and Ultraefficient Microwave Absorption Properties of Trace N‐Doped Two‐Dimensional Carbon‐Based Nanocomposites Loaded with Multi‐Rare Earth Oxides

A high efficiency and great tunability of bandwidth and absorption‐range electromagnetic wave absorber is proposed without precedent. A series of 2D carbon‐based nanocomposites with the loading of cerium oxide (CN‐Ce) and other types of rare earth oxides (CN‐REOs) can be successfully synthesized by a simple solvothermal‐sintering method. As‐synthesized 2D nanocomposites with local graphite‐like C₃N₄ structure and trace N‐doped are identified by transmission electron microscopy, X‐ray photoelectron spectroscopy, X‐ray powder diffraction, Fourier transform infrared spectroscopy, and Raman spectroscopy. The CN‐REOs and polyvinylidene fluoride composite absorbers with reflection loss values above ?40 dB are obtained in C‐band, X‐band, and Ku‐band, respectively. The empirical rules on effective bandwidth and frequency range are discovered and summarized, which can be successfully realized by simply tuning the doping amount or type of REO. The mechanism is explained by enhanced attenuation and tunable impedance matching. In addition co‐filled samples by two types of CN‐REOs nanocomposites are prepared to support these findings and inspire the preparation of absorber with desirable frequency band in the range of 2–18 GHz.     

Crafting Mussel‐Inspired Metal Nanoparticle‐Decorated Ultrathin Graphitic Carbon Nitride for the Degradation of Chemical Pollutants and Production of Chemical Resources

The development of efficient photocatalysts for the degradation of organic pollutants and production of hydrogen peroxide (H₂O₂) is an attractive two‐in‐one strategy to address environmental remediation concerns and chemical resource demands. Graphitic carbon nitride (g‐C₃N₄) possesses unique electronic and optical properties. However, bulk g‐C₃N₄ suffers from inefficient sunlight absorption and low carrier mobility. Once exfoliated, ultrathin nanosheets of g‐C₃N₄ attain much intriguing photocatalytic activity. Herein, a mussel‐inspired strategy is developed to yield silver‐decorated ultrathin g‐C₃N₄ nanosheets (Ag@U‐g‐C₃N₄‐NS). The optimum Ag@U‐g‐C₃N₄‐NS photocatalyst exhibits enhanced electrochemical properties and excellent performance for the degradation of organic pollutants. Due to the photoformed valence band holes and selective two‐electron reduction of O₂ by the conduction band electrons, it also renders an efficient, economic, and green route to light‐driven H₂O₂ production with an initial rate of 0.75 × 10^?6 m min^?1. The improved photocatalytic performance is primarily attributed to the large specific surface area of the U‐g‐C₃N₄‐NS layer, the surface plasmon resonance effect induced by Ag nanoparticles, and the cooperative electronic capture properties between Ag and U‐g‐C₃N₄‐NS. Consequently, this unique photocatalyst possesses the extended absorption region, which effectively suppresses the recombination of electron–hole pairs and facilitates the transfer of electrons to participate in photocatalytic reactions.     

Single Ni Atoms Anchored on Porous Few‐Layer g‐C3N4 for Photocatalytic CO2 Reduction: The Role of Edge Confinement

It is greatly intriguing yet remains challenging to construct single‐atomic photocatalysts with stable surface free energy, favorable for well‐defined atomic coordination and photocatalytic carrier mobility during the photoredox process. Herein, an unsaturated edge confinement strategy is defined by coordinating single‐atomic‐site Ni on the bottom‐up synthesized porous few‐layer g‐C₃N₄ (namely, Ni₅‐CN) via a self‐limiting method. This Ni₅‐CN system with a few isolated Ni clusters distributed on the edge of g‐C₃N₄ is beneficial to immobilize the nonedged single‐atomic‐site Ni species, thus achieving a high single‐atomic active site density. Remarkably, the Ni₅‐CN system exhibits comparably high photocatalytic activity for CO₂ reduction, giving the CO generation rate of 8.6 µmol g^?1 h^?1 under visible‐light illumination, which is 7.8 times that of pure porous few‐layer g‐C₃N₄ (namely, CN, 1.1 µmol g^?1 h^?1). X‐ray absorption spectrometric analysis unveils that the cationic coordination environment of single‐atomic‐site Ni center, which is formed by Ni‐N doping‐intercalation the first coordination shell, motivates the superiority in synergistic N–Ni–N connection and interfacial carrier transfer. The photocatalytic mechanistic prediction confirms that the introduced unsaturated Ni‐N coordination favorably binds with CO₂, and enhances the rate‐determining step of intermediates for CO generation.     

Synergy of Dopants and Defects in Graphitic Carbon Nitride with Exceptionally Modulated Band Structures for Efficient Photocatalytic Oxygen Evolution

Electronic structure greatly determines the band structures and the charge carrier transport properties of semiconducting photocatalysts and consequently their photocatalytic activities. Here, by simply calcining the mixture of graphitic carbon nitride (g‐C₃N₄) and sodium borohydride in an inert atmosphere, boron dopants and nitrogen defects are simultaneously introduced into g‐C₃N₄. The resultant boron‐doped and nitrogen‐deficient g‐C₃N₄ exhibits excellent activity for photocatalytic oxygen evolution, with highest oxygen evolution rate reaching 561.2 µmol h^?1 g^?1, much higher than previously reported g‐C₃N₄. It is well evidenced that with conduction and valence band positions substantially and continuously tuned by the simultaneous introduction of boron dopants and nitrogen defects into g‐C₃N₄, the band structures are exceptionally modulated for both effective optical absorption in visible light and much increased driving force for water oxidation. Moreover, the engineered electronic structure creates abundant unsaturated sites and induces strong interlayer C–N interaction, leading to efficient electron excitation and accelerated charge transport. In the present work, a facile approach is successfully demonstrated to engineer the electronic structures and the band structures of g‐C₃N₄ with simultaneous introduction of dopants and defects for high‐performance photocatalytic oxygen evolution, which can provide informative principles for the design of efficient photocatalysis systems for solar energy conversion.     

Phytosynthesis of Cu/rGO using Euphorbia cheiradenia Boiss extract and study of its ability in the reduction of organic dyes and 4‐nitrophenol in aqueous medium

For the first time, copper nanoparticles (Cu NPs) superficially deposited on reduced graphene oxide (rGO) using Euphorbia cheiradenia Boiss leaf aqueous media. A beneficial series of analytical methods was used to characterise E. cheiradenia Boiss leaf extract and involved nanostructures. The Cu/rGO nanocomposite (NC) obtained from the conversion of Cu²⁺ ions to Cu NPs and GO to rGO undergoes the plant extract and used as a heterogeneous and reusable nanocatalyst for the destruction of 4‐nitrophenol, rhodamine B, methylene blue, methyl orange and congo red using sodium borohydride at ambient temperature. In addition, Cu/rGO NC has reusability for many times in the reduction reactions with no decreasing of its catalytic capability.Inspec keywords: catalysts, nanofabrication, nanocomposites, dyes, nanoparticles, reduction (chemical), copper, graphene compoundsOther keywords: phytosynthesis, organic dyes, reusable nanocatalyst, Euphorbia cheiradenia Boiss extract, 4‐nitrophenol, nanoparticles, graphene oxide, nanocomposites, methylene blue, methyl orange, congo red, sodium borohydride, catalytic capability, Cu‐CO     

Synthesis and characterization of binary transition metal oxide/reduced graphene oxide nanocomposites and its enhanced electrochemical properties for supercapacitor applications

SnO₂/Co₃O₄ (BTMO) with reduced graphene oxide (rGO) nanocomposite were synthesized by co-precipitation method to determine its electrochemical properties for the betterment of Supercapacitor applications. The XRD pattern of BTMO/rGO nanocomposite shows tetragonal rutile and spinal cubic structure. The XRD peak of BTMO/rGO nanocomposite is comparatively broader than the BTMO nanocomposite and bare nanoparticles due to the presence of high surface area rGO. From the SEM image it is observed that the BTMO nanocomposite has comparatively larger particles than the bare nanoparticles and BTMO/rGO nanocomposites. Hence, the BTMO/rGO nanocomposite has alteration in surface to volume ratio and improved electron conductivity were observed with increased integral area and current such as 2.5117?×?10^?4 A/s and 3.1686?×?10^?4 A respectively in CV behavior, when it is compared to BTMO nanocomposite and bare nanoparticles. The BTMO/rGO nanocomposite also has an increased specific capacitance value of 317.2 F/g at 1 A/g. The increased specific capacitance value of BTMO/rGO nanocomposites are mainly due to the synergistic effect between SnO₂/Co₃O₄ and rGO. Hence, it may be responsible for the improved electron conductivity, due to the free diffusion pathway for the fast ion movement and also it has easily ion accessibility nature to the storage sites makes the materials with both the electric double layer capacitance and pseudocapacitance behavior. Hence, BTMO/rGO nanocomposite would be a promising candidate material for energy storage supercapacitor application.     

Photo-electrochemical and enhanced photocatalytic activity of CdS/rGO nanocomposites prepared by hydrothermal method

CdS/rGO nanocomposites with different mass ratio of rGO were fabricated via a facile one-pot hydrothermal method. The influences of different ratios on the microstructure, photo-electrochemical, and photocatalytic properties of the as-prepared samples were investigated. The experimental results show that CdS/rGO nanocomposites are hexagonal structure, one-dimensional CdS nanorods decorated on the surface of graphene. CdS/rGO nanocomposites show excellent visible light absorption and the band gap smaller than that of pure CdS and occur red shift. The photoluminescence spectra, transient photocurrent response and electrochemical impedance spectra indicate this nanostructure can accelerate the separation and migration efficiency of photogenerated electron–hole pairs, inhibit the recombination of photogenerated carries and and enhance electron transportation in the photocatalytic reactions. CdS/rGO nanocomposites display enhanced photocatalytic activity in degradation of MO under the simulated sunlight irradiation than that of pure CdS. In addition, in the photocatalytic degradation process ·O₂^? and ·OH play the key role.

     

Merging Single‐Atom‐Dispersed Iron and Graphitic Carbon Nitride to a Joint Electronic System for High‐Efficiency Photocatalytic Hydrogen Evolution

Scalable and sustainable solar hydrogen production via photocatalytic water splitting requires extremely active and stable light‐harvesting semiconductors to fulfill the stringent requirements of suitable energy band position and rapid interfacial charge transfer process. Motivated by this point, increasing attention has been given to the development of photocatalysts comprising intimately interfaced photoabsorbers and cocatalysts. Herein, a simple one‐step approach is reported to fabricate a high‐efficiency photocatalytic system, in which single‐site dispersed iron atoms are rationally integrated on the intrinsic structure of the porous crimped graphitic carbon nitride (g‐C₃N₄) polymer. A detailed analysis of the formation process shows that a stable complex is generated by spontaneously coordinating dicyandiamidine nitrate with iron ions in isopropanol, thus leading to a relatively complicated polycondensation reaction upon thermal treatment. The correlation of experimental and computational results confirms that optimized electronic structures of Fe@g‐C₃N₄ with an appropriate d‐band position and negatively shifting Fermi level can be achieved, which effectively gains the reducibility of electrons and creates more active sites for the photocatalytic reactions. As a result, the Fe@g‐C₃N₄ exhibits a highlighted intramolecular synergistic effect, performing greatly enhanced solar‐photon‐driven activities, including excellent photocatalytic hydrogen evolution rate (3390 µmol h^?1 g^?1, λ > 420 nm) and a reliable apparent quantum efficiency value of 6.89% at 420 nm.     

Surface Engineering for Extremely Enhanced Charge Separation and Photocatalytic Hydrogen Evolution on g‐C3N4

Reinforcing the carrier separation is the key issue to maximize the photocatalytic hydrogen evolution (PHE) efficiency of graphitic carbon nitride (g‐C₃N₄). By a surface engineering of gradual doping of graphited carbon rings within g‐C₃N₄, suitable energy band structures and built‐in electric fields are established. Photoinduced electrons and holes are impelled into diverse directions, leading to a 21‐fold improvement in the PHE rate.     

Tubular g‐C3N4 Isotype Heterojunction: Enhanced Visible‐Light Photocatalytic Activity through Cooperative Manipulation of Oriented Electron and Hole Transfer

A tubular g‐C₃N₄ isotype heterojunction (TCNH) photocatalyst was designed for cooperative manipulation of the oriented transfer of photogenerated electrons and holes to pursue high catalytic performance. The adduct of cyanuric acid and melamine (CA·M) is first hydrothermally treated to assemble into hexagonal prism crystals; then the hybrid precursors of urea and CA·M crystals are calcined to form tubular g‐C₃N₄ isotype heterojunctions. Upon visible‐light irradiation, the photogenerated electrons transfer from g‐C₃N₄ (CA·M) to g‐C₃N₄ (urea) driven by the conduction band offset of 0.05 eV, while the photogenerated holes transfer from g‐C₃N₄ (urea) to g‐C₃N₄ (CA·M) driven by the valence band offset of 0.18 eV, which renders oriented transfer of the charge carriers across the heterojunction interface. Meanwhile, the tubular structure of TCNH is favorable for oriented electron transfer along the longitudinal dimension, which greatly decreases the chance of charge carrier recombination. Consequently, TCNH exhibits a high hydrogen evolution rate of 63 μmol h^?1 (0.04 g, λ > 420 nm), which is nearly five times of the pristine g‐C₃N₄ and higher than most of the existing g‐C₃N₄ photocatalysts. This study demonstrates that isotype heterojunction structure and tubular structure can jointly manipulate the oriented transfer of electrons and holes, thus facilitating the visible‐light photocatalysis.     

Hierarchical Porous O‐Doped g‐C3N4 with Enhanced Photocatalytic CO2 Reduction Activity

Artificial photosynthesis of hydrocarbon fuels by utilizing solar energy and CO₂ is considered as a potential route for solving ever‐increasing energy crisis and greenhouse effect. Herein, hierarchical porous O‐doped graphitic carbon nitride (g‐C₃N₄) nanotubes (OCN‐Tube) are prepared via successive thermal oxidation exfoliation and curling‐condensation of bulk g‐C₃N₄. The as‐prepared OCN‐Tube exhibits hierarchically porous structures, which consist of interconnected multiwalled nanotubes with uniform diameters of 20–30 nm. The hierarchical OCN‐Tube shows excellent photocatalytic CO₂ reduction performance under visible light, with methanol evolution rate of 0.88 µmol g^?1 h^?1, which is five times higher than bulk g‐C₃N₄ (0.17 µmol g^?1 h^?1). The enhanced photocatalytic activity of OCN‐Tube is ascribed to the hierarchical nanotube structure and O‐doping effect. The hierarchical nanotube structure endows OCN‐Tube with higher specific surface area, greater light utilization efficiency, and improved molecular diffusion kinetics, due to the more exposed active edges and multiple light reflection/scattering channels. The O‐doping optimizes the band structure of g‐C₃N₄, resulting in narrower bandgap, greater CO₂ affinity, and uptake capacity as well as higher separation efficiency of photogenerated charge carriers. This work provides a novel strategy to design hierarchical g‐C₃N₄ nanostructures, which can be used as promising photocatalyst for solar energy conversion.     

New 2D Carbon Nitride Organic Materials Synthesis with Huge‐Application Prospects in CN Photocatalyst

In recent years, 2D materials are attracting increased attention because of their excellent properties. In this paper, new 2D carbon nitride (CN) organic materials are successfully prepared on the basis of the organic synthesis theory, and the thickness is about 1.5 nm. This new 2D CN organic material further strengthens the 2D materials family. Meanwhile, their synthetic mechanism is theoretically speculated. Then CN photocatalysts of several structures are obtained by roasting 2D CN organic materials. Through the photocatalytic hydrogen production experiments, the results exhibit that these kinds of photocatalysts have good photocatalytic effects compared to common g‐C₃N₄.     

Creating Graphitic Carbon Nitride Based Donor‐π–Acceptor‐π–Donor Structured Catalysts for Highly Photocatalytic Hydrogen Evolution

Conjugated polymers with tailored donor–acceptor units have recently attracted considerable attention in organic photovoltaic devices due to the controlled optical bandgap and retained favorable separation of charge carriers. Inspired by these advantages, an effective strategy is presented to solve the main obstructions of graphitic carbon nitride (g‐C₃N₄) photocatalyst for solar energy conversion, that is, inefficient visible light response and insufficient separation of photogenerated electrons and holes. Donor‐π–acceptor‐π–donor polymers are prepared by incorporating 4,4′‐(benzoc 1,2,5 thiadiazole‐4,7‐diyl) dianiline (BD) into the g‐C₃N₄ framework (UCN‐BD). Benefiting from the visible light band tail caused by the extended π conjugation, UCN‐BD possesses expanded visible light absorption range. More importantly, the BD monomer also acts as an electron acceptor, which endows UCN‐BD with a high degree of intramolecular charge transfer. With this unique molecular structure, the optimized UCN‐BD sample exhibits a superior performance for photocatalytic hydrogen evolution upon visible light illumination (3428 µmol h^?1 g^?1), which is nearly six times of that of the pristine g‐C₃N₄. In addition, the photocatalytic property remains stable for six cycles in 3 d. This work provides an insight into the synthesis of g‐C₃N₄‐based D‐π–A‐π–D systems with highly visible light response and long lifetime of intramolecular charge carriers for solar fuel production.     

Proton‐Functionalized Two‐Dimensional Graphitic Carbon Nitride Nanosheet: An Excellent Metal‐/Label‐Free Biosensing Platform

Ultrathin graphitic carbon nitride (g‐C₃N₄) nanosheets, due to their interesting two‐dimensional graphene‐like structure and unique physicochemical properties, have attracted great research attention recently. Here, a new approachis developed to prepare, for the first time, proton‐functionalized ultrathin g‐C₃N₄ nanosheets by sonication‐exfoliation of bulk g‐C₃N₄ under an acid condition. This method not only reduces the exfoliation time from more than 10 h to 2 h, but also endows the nanosheets with positive charges. Besides retaining the properties of g‐C₃N₄, the obtained nanosheets with the thickness of 2–4 nm (i.e., 6–12 atomic monolayers) also exhibit large specific surface area of 305 m² g^?1, enhanced fluorescence intensity, and excellent water dispersion stability due to their surface protonation and ultrathin morphology. The well‐dispersed protonated g‐C₃N₄ nanosheets are able to interact with negatively charged heparin, which results in the quenching of g‐C₃N₄ fluorescence. A highly sensitive and highly selective heparin sensing platform based on protonated g‐C₃N₄ nanosheets is established. This metal‐free and fluorophore label‐free system can reach the lowest heparin detection limit of 18 ng mL^?1.     

Construction of hybrid g-C3N4/CdO nanocomposite with improved photodegradation activity of RhB dye under visible light irradiation

The hybrid graphitic carbon nitride-cadmium oxide (g-C₃N₄/CdO) nanocomposite was fabricated using chemical precipitation and self-assembly method. The photocatalysts were characterised by XRD, XPS, FTIR, BET, TEM, FESEM, UV-Vis and PL spectroscopy. Based on the optical study, visible light harvesting was improved and the band gap of bulk g-C₃N₄ to hybrid g-C₃N₄/CdO nanocomposite was greatly reduced from 2.72 eV to 2.35 eV, signifying a better charge carrier mobility. The photocatalytic activity were further assessed by conducting rhodamine B (RhB) photodegradation reaction using visible light. An excellent dye removal efficiency of 96% was achieved when 1.5 g/L of hybrid g-C₃N₄/CdO nanocomposite was used with an initial concentration of 10 ppm for 120 min whereas only 66% of RhB was removed by bulk g-C₃N₄ within the same operating conditions. Besides, reusability tests were carried out and evidenced that hybrid g-C₃N₄/CdO nanocomposite can be recycled up to four times by retaining the degradation efficiency. The scavenging studies confirmed that the RhB photodegradation using hybrid g-C₃N₄/CdO nanocomposite was controlled by valance band h⁺ and O²⁻ oxidation reactions. Conclusively, the inclusion of CdO onto g-C₃N₄ resulted in remarkable photocatalytic activity for dye degradation applications.     

Nanogap Engineered Plasmon‐Enhancement in Photocatalytic Solar Hydrogen Conversion

Graphitic carbon nitride modified with plasmonic Ag@SiO₂ core–shell nanoparticles (g‐C₃N₄/Ag@SiO₂) are proposed for enhanced photocatalytic solar hydrogen evolution under visible light. Nanosized gaps between the plasmonic Ag nanoparticles (NPs) and g‐C₃N₄ are created and precisely modulated to be 8, 12, 17, and 21 nm by coating SiO₂ shells on the Ag NPs. The optimized photocatalytic hydrogen production activity for g‐C₃N₄/Ag@SiO₂ is achieved with a nanogap of 12 nm (11.4 μmol h⁻¹) to be more than twice as high as that of pure g‐C₃N₄ (5.6 μmol h⁻¹). The plasmon resonance energy transfer (PRET) effect of Ag NPs is innovatively proved from a physical view on polymer semiconductors for photoredox catalysis. The PRET effect favors the charge carrier separation by inducing electron–hole pairs efficiently formed in the near‐surface region of g‐C₃N₄. Furthermore, via engineering the width of the nanogap, the PRET and energy‐loss Förster resonance energy transfer processes are perfectly balanced, resulting in considerable enhancement of photocatalytic hydrogen production activity over the g‐C₃N₄/Ag@SiO₂ plasmonic photocatalyst.     

Green gelatin-assisted: Synthesis of Co3O4NPs@rGO nanopowder for highly efficient magnetically separable methylene orange dye degradation

GO and Co(NO₃)₂ were respectively used as rGO and Co₃O₄ precursors for preparing magnetically separable Co₃O₄NPs attached Co₃O₄NPs@rGO nanocomposites by a straightforward sol–gel technique. To characterize the nanocomposite materials, FESEM, EDX, elemental mapping, XRD, FTIR, Raman spectroscopy, UV–vis, VSM and BET were employed. When exposed to UV rays, the nanocomposite showed extraordinary photocatalytic degradation of MO dye. According to the measurements of photocatalytic activity, the highly efficient photocatalytic efficiency of the nanocomposite could be attributed to preventing electron-hole recombination by highly effective electron transfer between rGO and semiconductor NPs. The nanocomposite succeeded in the efficient degradation of MO dye, even after five photocatalytic cycles.     

An All‐Organic Semiconductor C3N4/PDINH Heterostructure with Advanced Antibacterial Photocatalytic Therapy Activity

Antibacterial photocatalytic therapy has been reported as a promising alternative water disinfection technology for combating antibiotic‐resistant bacteria. Numerous inorganic nanosystems have been developed as antibiotic replacements for bacterial infection treatment, but these are limited due to the toxicity risk of heavy metal species. Organic semiconductor photocatalytic materials have attracted great attention due to their good biocompatibility, chemically tunable electronic structure, diverse structural flexibility, suitable band gap, low cost, and the abundance of the resources they require. An all‐organic composite photocatalytic nanomaterial C₃N₄/perylene‐3,4,9,10‐tetracarboxylic diimide (PDINH) heterostructure is created through recrystallization of PDINH on the surface of C₃N₄ in situ, resulting in enhanced photocatalytic efficiency due to the formation of a basal heterostructure. The absorption spectrum of this composite structure can be extended from ultraviolet to near‐infrared light (750 nm), enhancing the photocatalytic effect to produce more reactive oxygen species, which have an excellent inactivation effect on both Gram‐negative and positive bacteria, while demonstrating negligible toxicity to normal tissue cells. An efficient promotion of infectious wound regeneration in mice with Staphylococcus aureus infected dermal wounds is demonstrated. This all‐organic heterostructure shows great promise for use in wound disinfection.     

Metal‐Free 2D/2D Phosphorene/g‐C3N4 Van der Waals Heterojunction for Highly Enhanced Visible‐Light Photocatalytic H2 Production

The generation of green hydrogen (H₂) energy using sunlight is of great significance to solve the worldwide energy and environmental issues. Particularly, photocatalytic H₂ production is a highly promising strategy for solar‐to‐H₂ conversion. Recently, various heterostructured photocatalysts with high efficiency and good stability have been fabricated. Among them, 2D/2D van der Waals (VDW) heterojunctions have received tremendous attention, since this architecture can promote the interfacial charge separation and transfer and provide massive reactive centers. On the other hand, currently, most photocatalysts are composed of metal elements with high cost, limited reserves, and hazardous environmental impact. Hence, the development of metal‐free photocatalysts is desirable. Here, a novel 2D/2D VDW heterostructure of metal‐free phosphorene/graphitic carbon nitride (g‐C₃N₄) is fabricated. The phosphorene/g‐C₃N₄ nanocomposite shows an enhanced visible‐light photocatalytic H₂ production activity of 571 µmol h^?1 g^?1 in 18 v% lactic acid aqueous solution. This improved performance arises from the intimate electronic coupling at the 2D/2D interface, corroborated by the advanced characterizations techniques, e.g., synchrotron‐based X‐ray absorption near‐edge structure, and theoretical calculations. This work not only reports a new metal‐free phosphorene/g‐C₃N₄ photocatalyst but also sheds lights on the design and fabrication of 2D/2D VDW heterojunction for applications in catalysis, electronics, and optoelectronics.     

Photoassisted Construction of Holey Defective g‐C3N4 Photocatalysts for Efficient Visible‐Light‐Driven H2O2 Production

Holey defective g‐C₃N₄ photocatalysts, which are easily prepared via a novel photoassisted heating process, are reported. The photoassisted treatment not only helps to create abundant holes, endowing g‐C₃N₄ with more exposed catalytic active sites and crossplane diffusion channels to shorten the diffusion distance of both reactants from the surface to bulk and charge carriers from the bulk to surface, but also introduces nitrogen vacancies in the tri‐s‐triazine repeating units of g‐C₃N₄, inducing the narrowing of intrinsic bandgap and the formation of defect states within bandgap to extend the visible‐light absorption range and suppress the radiative electron–hole recombination. As a result, the holey defective g‐C₃N₄ photocatalysts show much higher photocatalytic activity for H₂O₂ production with optimized enhancement up to ten times higher than pristine bulk g‐C₃N₄. The newly developed synthetic strategy adopted here enables the sufficient utilization of solar energy and shows rather promising for the modification of other materials for efficient energy‐related applications.