Separation Of Photoexcited Charge Carriers Research Articles

Engineering ZnIn2S4 with efficient charge separation and utilization for synergistic accelerate dual-function photocatalysis

Combining photocatalytic reduction with organic synthetic oxidation in the same photocatalytic redox system can effectively utilize photoexcited electrons and holes from solar to chemical energy. Here, we stabilized 0D Au clusters on the substrate surface of Zn vacancies modified 2D ZnIn2S4 (ZIS-V) nanosheets by chemically bonding Au-S interaction, forming surfactant functionalized Au/ZIS-V photocatalyst, which can not only synergistic accelerate the selective oxidation of phenylcarbinol to value-added products coupled with clean energy hydrogen production but also further drive photocatalytic CO2-to-CO conversion. An internal electric field of Au/ZIS-V ohmic junction and Zn vacancies synchronously promote the photoexcited charge carrier separation and transfer to optimized active sites for redox reactions. Compared with CO2 reduction in water and the pristine ZnIn2S4, the reaction thermodynamics and kinetics of CO2 reduction over the Au/ZIS-V were simultaneously improved about 11.09 and 45.51 times, respectively. Moreover, the photocatalytic redox mechanisms were also profoundly studied by 13CO2 isotope tracing tests, in situ electron paramagnetic resonance (in situ EPR), in situ X-ray photoelectron spectroscopy (in situ XPS), in situ diffuse reflection infrared Fourier transform spectroscopy (in situ DRIFTS) and density functional theory (DFT) characterizations, etc. These results demonstrate the advantages of vacancies coupled with metal clusters in the synergetic enhancement of photocatalytic redox performance and have great potential applications in a wide range of environments and energy.

Enhanced light harvesting ability in hollow Pt/TiO2 nanoreactor for boosting tetracycline photodegradation

Utilizing solar energy to decompose tetracycline (TC) is a green strategy to treat wastewater. Herein, a heterogeneous hollow structured TiO2 decorated Pt nanoparticles were successfully designed and synthesized via hard-template approach and photo-deposition process toward TC photodegradation. The Pt nanoparticles loaded on the surface of hollow structured TiO2 can increase the visible light absorption due to the local surface plasmon resonance (LSPR) effect. Furthermore, owing to the tough electron oscillation of the LSPR excitation, the plasmonic hot holes on the surface of Pt nanoparticles can capture the electrons of TiO2, effectively facilitating the separation of photo-excited charge carriers because of the formation of Schottky junction constructed between Pt and TiO2. Combined the natural merits of shorten conveying path of charge carriers and physical structural stability for hollow structure, the optimal Pt/TiO2 hetero-junction hybrid showed superior photocatalytic activity and durability for TC photodegradation with the degradation efficiency of 93.8 ​% after 30 ​min and the rate constant of 0.09196 min−1 under 300 ​W Xe lamp irradiation. This work displays a heterogeneous hybrids catalyst based on eco-friendly metal and semiconductor materials which can be used in the fields including without limitation TC photodegradation.

Atomically dispersed magnesium enhancing reactive oxygen species generation over g-C3N4 nanosheets for efficient photocatalytic NO removal

Photoinduced reactive oxygen species (ROSs)-involving nitrogen oxide (NOx) abatement offers a green way to mitigate environmental air pollution. Developing cost-effective photocatalysts remains challenging yet crucial. Herein, an atomically dispersed Mg-modified g-C3N4 nanosheet photocatalyst (xMg-CN) with excellent photoactivity is developed. The 1.0Mg-CN sample delivers a high NO removal rate of 52.3% under visible light irradiation within 30 min, far surpassing the Mg-free analog (CN, 41.2%). Moreover, a suppressed NO2 by-product discharge can be achieved. The introduction of Mg single atoms (SAs) alters the charge density distribution on the triazine ring plane of g-C3N4, inducing the formation of a built-in electric field, which improves the photoexcited charge carrier separation. Additionally, Mg SAs contribute to the adsorption and activation of O2 molecules, resulting in enhanced ROSs production, as evidenced by the experiments and theoretical simulations. The findings shed light on the role of SAs in designing highly efficient g-C3N4-based photocatalysts for air purification.

Exploring a Ni-N4 Active Site-Based Conjugated Microporous Polymer Z-Scheme Heterojunction Through Covalent Bonding for Visible Light-Driven Photocatalytic CO2 Conversion in Pure Water.

Designing photocatalysts with efficient charge transport and abundant active sites for photocatalytic CO2 reduction in pure water is considered a potential approach. Herein, a nickel-phthalocyanine containing Ni-N4 active sites-based conjugated microporous polymer (NiPc-CMP), offering highly dispersed metal active sites, satisfactory CO2 adsorption capability, and excellent light harvesting properties, is engineered as a photocatalyst. By virtue of the covalently bonded bridge, an atomic-scale interface between the NiPc-CMP/Bi2 WO6 Z-scheme heterojunction withstrong chemical interactions is obtained. The interface creates directional charge transport highways and retains a high redox potential, thereby enhancing the photoexcited charge carrier separation and photocatalytic efficiency. Consequently, the optimal NiPc-CMP/Bi2 WO6 (NCB-3) achieves efficient photocatalytic CO2 reduction performance in pure water under visible-light irradiation without any sacrificial agent or photosensitizer, affording a CO generation rate of 325.9µmol g-1 with CO selectivity of 93% in 8h, outperforming those of Bi2 WO6 and NiPc-CMP, individually. Experimental and theoretical calculations reveal the promotion of interfacial photoinduced electron separation and the role of Ni-N4 active sites in photocatalytic reactions. This study presents a high-performance CMP-based Z-scheme heterojunction with an effective interfacial charge-transfer route and rich metal active sites for photocatalytic CO2 conversion.

Efficient splitting of alcohols into hydrogen and C–C coupled products over ultrathin Ni-doped ZnIn2S4 nanosheet photocatalyst

Integrating selective organic synthesis with hydrogen (H2) evolution in one photocatalytic redox reaction system sheds light on the underlying approach for concurrent employment of photogenerated electrons and holes towards efficient production of solar fuels and chemicals. In this work, a facile one-pot oil bath method has been proposed to fabricate a noble metal-free ultrathin Ni-doped ZnIn2S4 (ZIS/Ni) composite nanosheet for effective solar-driven selective dehydrocoupling of benzyl alcohol into value-added C–C coupled hydrobenzoin and H2 fuel, which exhibits higher performance than pure ZIS nanosheet. The remarkably improved photoredox activity of ZIS/Ni is mainly attributed to the optimized electron structure featuring narrower band gap and suitable energy band position, which facilitates the ability of light harvesting and photoexcited charge carrier separation and transfer. Furthermore, it has been demonstrated that it is feasible to employ ZIS/Ni for various aromatic alcohols dehydrocoupling to the corresponding C–C coupled products. It is expected that this work can stimulate further interest on the establishment of innovative photocatalytic redox platform coupling clean solar fuels synthesis and selective organic conversion in a sustainable manner.

A zero-dimensional/two-dimensional Ag–Ag2S–CdS plasmonic nanohybrid for rapid photodegradation of organic pollutant by solar light

Herein, the two synthesis strategies are employed for rational design of 0D/2DAg-Ag2S–CdS heterojunctions towards photocatalytic degradation of methyl orange (MO) under simulated solar light. As the first strategy, a ternary Ag–Ag2S–CdS nanosheet (NS) heterojunction was fabricated via combined cation exchange and photo-reduction (CEPR) method (Ag–Ag2S–CdS/CEPR). The second strategy employed coprecipitation (CP) method (Ag–Ag2S–CdS/CP). Strikingly, SEM, TEM and HR-TEM images are manifested the first strategy is beneficial for retaining the original thickness (20.2 nm) of CdS NSs with a dominant formation of metallic Ag, whereas the second strategy increases the thickness (33.4 nm) of CdS NSs with a dominant formation of Ag2S. The Ag–Ag2S–CdS/CEPR exhibited 1.8-fold and 3.5-fold enhancement in photocatalytic activities as compared to those of Ag–Ag2S–CdS/CP and bare CdS NSs, respectively. This enhanced photocatalytic activity could be ascribed to fact that the first strategy produces a high-quality interface with intimate contact between the Ag–Ag2S–CdS heterojunctions, resulting in enhanced separation of photo-excited charge carriers, extended light absorption, and enriched active-sites. Furthermore, the degradation efficiency of Ag–Ag2S–CdS/CEPR was significantly reduced to ∼5% in the presence of BQ (•O2− scavenger), indicating that •O2− is the major active species that can decompose MO dye under simulated solar light.

Tailored fabrication of TiO2/In2O3 hybrid mesoporous nanofibers towards enhanced photocatalytic performance

In present work, we report the fabrication of mesoporous TiO2/In2O3 nanofibers photocatalyst via the combination of electrospinning and hydrothermal method, in which In2O3 were uniformly grown on electrospun TiO2 nanofibers. The mass loading of In2O3 nanostructures and mesoporous nanostructure could be easily controlled by adjusting raw materials weight of In2O3 within the hydrothermal solutions. The as-prepared photocatalyst were also employed to study their photocatalytic performance for organic decomposition. It is found that TiO2/In2O3 composites showed significantly enhanced photocatalytic efficiency as compared to that of pristine TiO2 and In2O3 photocatalysts for RhB degradation. The enhanced performance could be attributed to the combined effects of the extended visible-light response range, efficient separation of photo-excited charge carriers and increased reaction active sites.

Synergistic effects of Tin sulfide Nitrogen-doped titania Nanobelt-Modified graphitic carbon nitride nanosheets with outstanding photocatalytic activity

Designing efficient ternary nanostructures is a feasible approach for energy production under simulated solar irradiation. In this study, excellent photoexcited charge carrier separation and enhanced visible-light response were achieved with nitrogen-doped titania nanobelts (N-TNBs), whose 1D geometry facilitated the fabrication of a heterostructure with SnS2 on the surface of graphitic carbon nitride (g-C3N4). We established the design of SnS2@N-TNB and SnS2@N-TNB/g-C3N4 heterostructures by in situ hydrothermal and ultrasonication processes, and achieved commendable simulated solar light driven photocatalytic H2 generation. UV–vis diffuse reflectance spectroscopy analysis revealed a red shift in the absorption spectra of the SnS2@N-TNB and SnS2@N-TNB/g-C3N4 samples. The H2 produced via SnS2@N-TNB-10/g-C3N4 (6730.8 µmol/g/h) was 2.6 times higher than that produced by SnS2@N-TNB (2515.1 µmol/g/h), and 299 times higher than that produced by N-TNB (22.5 µmol/g/h). The improved photocatalytic H2 production was attributed to the maximum interface contact between SnS2@N-TNB and g-C3N4, and to the improved visible-light absorption and effective charge-carrier separation. Therefore, the present study provides novel insights for combining the advantages of ternary materials to improve the conversion of solar energy to H2 fuel.

(Invited) Ultrathin Bismuth Oxyiodide Nano-Sheets for Photocatalytic Nitrogen Fixation Under Visible Light

Artificial photosynthesis of ammonia by using N2 and water under ambient temperature and pressure is an auspicious alternative for the high energy demanding Haber-Bosch process. Among the various photocatalysts, bismuth oxyhalides (BiOX, X = Cl, Br or I) show advantages due to their unique properties: (1) the 2D layered structure, not only enlarges the surface area, but also induces an internal electric field, which accelerates the separation of photo-excited charge carriers; (2) the surface enriched oxygen vacancies on the {001} or {010} facets are essential for the chemical adsorption and activation of N2; (3) the high intrinsic oxygen evolution activity allows an overall reaction without using sacrificial reagents. In this talk, I will show the photocatalytic generation of ammonia from water and nitrogen using ultrathin BiOI Nano-Sheets.

Steering the Charge Kinetics in Dual-Functional Photocatalysis by Surface Dipole Moments and Band Edge Modulation: A Defect Study in TiO2-ZnS-rGO Composites.

Developing an efficient photocatalyst for concurrent hydrogen production and environmental remediation by using solar energy is a challenge. Defect engineering, although it offers a strategical promise to enhance the photocatalytic performance, has limitations that come from the ambiguity surrounding its role. In the current work, a comprehensive study on defects in promoting the charge transfer, band edge modulation, and surface reaction was carried out. The excess electrons springing from defects act like donor states and cause band bending at the junction interface. Characterization techniques such as X-ray photoelectron spectroscopy, ultraviolet photoelectron spectroscopy, electron spin resonance, and photoluminescence were employed to investigate defect functionality, and its ultimate effect on photocatalytic performance was studied by simultaneous H2 production and methylene blue degradation. The role of graphene in optoelectronics and defect formation in the composite catalysts was explored. In addition, efforts have been made to unveil the reaction pathway for hydrogen evolution reaction and oxygen evolution reaction where excess defect density greatly hampered the quantum yield of the process. Results suggest that maintaining optimal defect concentration aborts the undesired thermodynamically favored back reactions. The conduction band and valence band values of the catalysts indicate that the photocatalytic mechanism was dominated by the electron pathway. Graphene acted as an effective electron sink when its concentration was around 2.5-3%. The superior activity of TiO2-ZnS-rGO was attributed to the narrow bandgap, rapid separation of photo-excited charge carriers, and favorable conduction band position for photocatalytic reactions. This work may assist in exploring the fundamental role of defects in driving the photocatalytic reactions and improve the selectivity in heterogeneous photocatalysis.

2D/2D Ti3C2 MXene/g-C3N4 nanosheets heterojunction for high efficient CO2 reduction photocatalyst: Dual effects of urea

In this paper, an ultrathin 2D/2D Ti3C2/g-C3N4 heterojunction was synthesized by direct calcination the mixture of bulk Ti3C2 and urea, where urea not only acts as the gas template to exfoliate Ti3C2 into nanosheets, but also as the precursor of g-C3N4 to craft Ti3C2/g-C3N4 heterojunction. CO2 photoreduction activity tests reveal that pure g-C3N4 (UCN) exhibits very weak photoactivity. However, when Ti3C2 was coupled with g-C3N4, the photocatalytic performance is soaringly enhanced. The optimal sample (10TC) shows the yields of 5.19 and 0.044 μmol h−1 g−1 for CO and CH4, respectively, and the total CO2 conversion is 8.1 times higher than that of UCN. The enhanced CO2 photoreduction activity is mainly attributed to the combined effects of (1) improved CO2 adsorption and activation, and (2) the construction of ultrathin 2D/2D Ti3C2/g-C3N4 heterojunction, where the intimate contact stimulates an efficient spatial separation of photo-excited charge carriers.

A Z-scheme photocatalyst for enhanced photocatalytic H2 evolution, constructed by growth of 2D plasmonic MoO3-x nanoplates onto 2D g-C3N4 nanosheets

Light-harvesting capacity and photoexcited charge carrier separation ability are two crucial requirements for high-efficiency semiconductor photocatalysis. Here, we report a plasmonic Z-scheme nanohybrid by hydrothermally in-situ growing two-dimensional (2D) oxygen-deficient molybdenum oxide (MoO3-x) nanoplates onto 2D graphitic carbon nitride (g-C3N4) nanosheets. The resultant 2D/2D MoO3-x/g-C3N4 nanohybrids not only construct a unique Z-scheme heterojunction, which improves the photogenerated charge carrier separation efficiency, but also possess numerous oxygen vacancies on the surface of MoO3-x, which could excite its plasmon resonance for extending spectrum adsorption. Importantly, the plasmon resonance can be readily designed by tailoring the oxygen vacancy concentration via an annealing in air. Benefiting from the synergetic effect of interfacial Z-scheme heterojunction and the tunable plasmon resonance of MoO3-x, the as-obtained nanohybrids achieve a remarkably improved photocatalytic H2 evolution efficiency. The optimal Z-scheme heterostructure presents 2.6 and 1.7 times higher of H2 evolution rate as compared to pure g-C3N4 and the annealing nanohybrid under visible light irradiation. Even under light irradiation with wavelength longer than 590 nm, the hybrid photocatalyst displays a H2 generation rate as high as 22.8 µmol h−1 due to the plasmonic sensitization effect. The result in our work can provide an alternative for fabricating Z-scheme heterostructures that take advantages of Z-scheme-induced charge carrier separation, accompanied with plasmon-enhanced light harvesting of semiconductor to advance the solar energy conversion efficiency in photocatalysis.

Interface Structure and Band Alignment of CZTS/CdS Heterojunction: An Experimental and First-Principles DFT Investigation.

We report a phase-pure kesterite Cu2ZnSnS4 (CZTS) thin films, synthesized using radio frequency (RF) sputtering followed by low-temperature H2S annealing and confirmed by XRD, Raman spectroscopy and XPS measurements. Subsequently, the band offsets at the interface of the CZTS/CdS heterojunction were systematically investigated by combining experiments and first-principles density functional theory (DFT) calculations, which provide atomic-level insights into the nature of atomic ordering and stability of the CZTS/CdS interface. A staggered type II band alignment between the valence and conduction bands at the CZTS/CdS interface was determined from Cyclic Voltammetry (CV) measurements and the DFT calculations. The conduction and valence band offsets were estimated at 0.10 and 1.21 eV, respectively, from CV measurements and 0.28 and 1.15 from DFT prediction. Based on the small conduction band offset and the predicted higher positions of the VBmax and CBmin for CZTS than CdS, it is suggested photogenerated charge carriers will be efficient separated across the interface, where electrons will flow from CZTS to the CdS and and vice versa for photo-generated valence holes. Our results help to explain the separation of photo-excited charge carriers across the CZTS/CdS interface and it should open new avenues for developing more efficient CZTS-based solar cells.

Photoexcited charge carrier behaviors in solar energy conversion systems from theoretical simulations

AbstractSolar energy bears great potential in the substitution of conventional fossil fuels to enable a sustainable world. In order to harness and use solar energy, photocatalytic and photovoltaic systems made of semiconductor materials have been developed to convert sunlight into energy (electricity) based on the photoelectrochemical effects. Photoelectric events are related with the light–energy (electricity) conversion process, including photon absorption, photoexcited charge carrier separation and recombination, charge carrier transport, and photocurrent generation, as well as electron plasmonic resonance. We focus on the recent state‐of‐the‐art simulation methods correspondingly mimicking these photogenerated charge carrier behaviors, taking electron–phonon, electron–exciton, and exciton–exciton interactions into account. Results can be obtained from the standard density function theory (DFT) for ground‐state properties, many‐body perturbation theory for band gap renormalization and optical absorption, time‐domain DFT in combination with nonadiabatic molecular dynamics for photoexcitation dynamics, nonequilibrium Green's function and self‐consistent theory for charge carrier transport properties, and classical Maxwell's equations in discrete dipole approximation for localized surface plasmon resonance absorption and near‐field enhancement. In combination of the results from these simulation methods, a complete and consistent picture describing the fundamental photoelectric process in light–energy (electricity) conversion could be obtained. Simulation results offer guidelines for experimental efforts and provide new basic insights into the underlying mechanisms and the design principles for next‐generation photocatalytic and photovoltaic devices of high solar light utilization efficiency.This article is categorized under: Structure and Mechanism > Computational Materials Science Electronic Structure Theory > Ab Initio Electronic Structure Methods Software > Simulation Methods

A Metal-Organic-Framework-Derived g-C3 N4 /α-Fe2 O3 Hybrid for Enhanced Visible-Light-Driven Photocatalytic Hydrogen Evolution.

As one of the most efficient systems for photocatalytic hydrogen evolution, the Z-Scheme system, consisting of different semiconductors with a reversible donor-acceptor pair, has attracted great attention. Considering the non-toxicity and low cost of photocatalysts, a series of g-C3 N4 /α-Fe2 O3 hybrids were rationally constructed based on the Z-Scheme mechanism for the first time, using a metal-organic framework template approach that can fine tune the compositions and properties of the hybrids. An optimized hybrid, g-C3 N4 /α-Fe2 O3 -2, exhibited prominent photocatalytic water splitting performance with a visible light response. Under irradiation of visible light (λ>420 nm), the hybrid shows a high durability and superior hydrogen production rate of 2066.2 μmol g-1 h-1 from water splitting, which is approximately three times greater than that of bulk g-C3 N4 because of the effective separation of photo-excited charge carriers by two narrow band gap semiconductors, tightly coupled with the Z-Scheme structural feature.

Photo-induced enhancement of the dark conductivity in nanocrystalline germanium/amorphous silicon composite thin films

A light-induced increase in the dark conductivity is observed in composite thin films consisting of hydrogenated amorphous silicon (a-Si:H) containing nanocrystalline germanium (nc-Ge) inclusions, synthesized by co-deposition in a dual-chamber plasma enhanced chemical vapor deposition system. Unlike the Staebler-Wronski effect or persistent photoconductivity observed in amorphous semiconductors, this photo-induced excess conductivity is observed even in composite nc-Ge/a-Si:H films with a minimal photosensitivity. The decay of the excess conductivity follows a single-exponential time dependence, with a temperature independent time constant. We propose that spatial separation of photo-excited charge carriers by the compositional morphology present in the film, with tunneling of photo-excited holes into the germanium nanocrystalline inclusions, is involved in the creation and removal of this effect.

Salt-template-assisted construction of honeycomb-like structured g-C3N4 with tunable band structure for enhanced photocatalytic H2 production

Honeycomb-like structured graphitic carbon nitride (g-C3N4) with tunable band structure was prepared through a one-step salt-template assisted approach. The honeycomb structure, cyano group defects and Na ion doping result in enhanced light absorption, improved photoexcited charge carrier separation, and up-shift of conduction band. As a consequence, the photocatalytic H2 evolution rate is about 5.2 times higher than that of the pristine graphitic carbon nitride. This newly developed approach provides a promising way to modify other functional materials through nanostructure design coupled with electronic modulation strategy simultaneously.

Experimental and first-principles studies of BiVO4/BiV1-xMnxO4-y n-n+ homojunction for efficient charge carrier separation in sunlight induced water splitting

Though bismuth vanadate (BiVO4) is extensively used as a photoactive material, its performance in harnessing solar energy is limited by ineffective separation of photo-excited charge carriers. We demonstrate here a concept of n-n+ homojunction of BiVO4/BiV1-xMnxO4-y, which improves its charge separation efficiency. Using first-principles theoretical calculations, we determine the effect of Mn substitution on oxygen vacancy formation energies and associated changes in the electronic structure of BiVO4. Showing that Mn substitution pushes the Fermi level of BiVO4 towards its conduction band, we predict that the associated enhanced bending of bands at the homojunction (BiVO4/BiV1-xMnxO4-y) facilitates efficient separation of charge carriers. With Mott-Schottky experiments, we verify the increased band bending at the n-n+ homojunction, and show that the maximum photocurrent density measured in a sample with n-n+ homojunction is ten times higher than that obtained of the pristine sample. Secondly, Mn substitution in BiVO4 also reduces the oxygen vacancy formation energy, promoting higher concentration of O-vacancies, further enhancing the photoelectrochemical response.

Amorphous tantalum oxyhydroxide homojunction: In situ construction for enhanced hydrogen production

An amorphous tantalum oxyhydroxide TaOx(OH)y homojunction is constructed by anchoring TaOx(OH)y (2x + y = 5) nanoparticles (NPs, size: 4–10 nm) in situ on the surface of TaOx(OH)y sphere (SP). The formation of amorphous homojunction (TaOx(OH)y NPs/SP) is demonstrated by detailed characterizations of transmission electron microscopy, thermogravimetric analysis/mass spectrometer, Fourier transfer infrared spectra and X-ray photoelectron spectroscopy. In the absence of cocatalyst, the constructed amorphous homojunction exhibits a photocatalytic H2 evolution rate of 311.1 μmol/g/h, about 5, 40 and 1000 times higher than that of 66.8 μmol/g/h for bare TaOx(OH)y SP, 7.6 μmol/g/h for commercial Ta2O5, and 0.3 μmol/g/h for the most widely used photocatalyst P25 (mixed-phase titania). The splendid performance is attributed to the special amorphous homojunction that produces a type-II band alignment and robust separation of photo-excited charge carriers, as uncovered by ultraviolet photoelectron, photoluminescence spectroscopy, and surface/transient photovoltage data. Our findings for amorphous homojunction may provide a new strategy of developing effective noncrystalline photocatalysts.

Facile synthesis of carbon-rich g-C3N4 by copolymerization of urea and tetracyanoethylene for photocatalytic degradation of Orange II

A novel graphitic carbon nitride (g-C3N4) photocatalyst was synthesized by a facile one-pot thermo-induced copolymerization method using urea and tetracyanoethylene (TCNE) for the first time. It was revealed that the as-prepared samples retained the original framework of g-C3N4, showed an increased surface area and enhanced visible-light harvesting, and promoted photoexcited charge carrier separation. The photocatalytic efficiency of the samples was investigated by degradation of Orange II solutions under visible-light irradiation (λ > 420 nm). The sample CN/TCNE-40 (40 mg TCNE in 30 g urea) achieved an Orange II degradation rate of about 91% in 60 min under visible-light irradiation, which is significantly higher than that of pristine g-C3N4 (51%). The pseudo-first-order rate constant for Orange II degradation on CN/TCNE-40 was 0.0317 min−1, 4.88 times as large as that of pristine g-C3N4. The CN/TCNE-40 sample maintained its high photoactivity after five cycles under identical experimental conditions and could degrade Orange II at various pH conditions under visible-light irradiation, confirming the high durability of the photocatalyst. The mechanism of the enhanced photocatalytic performance was also discussed. The results suggested that the CN/TCNE samples are potential photocatalysts for environmental and energy applications.