Visible Light Absorption Research Articles

Pd Nanoparticles Decorated CeZrOx for Enhanced Photocatalytic Hydrogenation of Biomass‐Derived Compounds

The photocatalytic conversion of biomass‐derived compounds into value‐added chemicals presents a promising protocol for the sustainable production of renewable chemicals. Our study explores the hydrogenation of biomass model compounds under visible light illumination. Zr was incorporated into the CeO2 framework, forming a CeZrOx(1:0.5) solid solution, confirmed by powder X‐ray diffraction (PXRD) and X‐ray photoelectron spectroscopy (XPS) analyses. The light uptake capacity of the CeZrOx solid solution was characterized using UV‐visible spectroscopy. Additionally, the band structure of the CeZrOx solid solution was assessed using valance band X‐ray photoelectron spectroscopy (VB‐XPS) and Ultraviolet photoelectron spectroscopy (UPS) analysis, revealing a Z‐Scheme, which was further confirmed by various control experiments. Upon decorating the CeZrOx(1:0.5) solid solution with 1 wt% palladium (Pd), the resulting 1Pd/CeZrOx(1:0.5) composite exhibited improved charge separation and enhanced visible light absorption capacity. This composite achieved ~99% conversion of furfural to tetrahydrofurfuryl alcohol under a 15 W blue LED illumination and 0.2 MPa hydrogen. Similarly, it demonstrated ~99% conversion of benzyl phenyl ether (BPE) to toluene and phenol under a 10 W blue LED illumination. Our findings elucidate the active sites and demonstrate the recyclability of mixed metal oxides for selective furfural hydrogenation and BPE hydrogenolysis under visible light.

Efficient tetracycline degradation using carbon quantum dot modified TiO2@LaFeO3 hollow core shell photocatalysts

Efficient harnessing of solar energy presents a significant challenge in environmental cleanup efforts. This study develops a highly effective carbon quantum dots-modified hollow core-shell TiO2-LaFeO3 heterojunction photocatalyst (CDs-TLFO). Structural analysis confirmed that nanosheets are loaded with CQDs, forming a hollow core-shell structure with intimate interconnection. Photocatalytic experiments reveal that CDs-TLFO degrads tetracycline hydrochloride (TC) 2.02 times faster than TLFO alone, and significantly outperformes h-TiO2 and LaFeO3 (11.28 and 2.78 times, respectively). This enhancement is attributed to CQDs acting as electron acceptors with upconversion properties, enhancing the separation of e–-h+ pairs and boosting visible light absorption. Integration of CQDs onto the TLFO surface creates numerous active sites and enhances visible light absorption. SEM and TEM tests confirm that the catalyst has a hollow core-shell structure. ESR tests and radical trapping experiments indicate that the high degradation efficiency of the catalyst mainly owns to the synergistic effect of hydroxyl radicals (·OH) and superoxide radicals (·O2−). The reusability and stability of the catalysts are investigated, potential TC degradation pathways are proposed as well as the photocatalytic reaction mechanism is revealed. This research introduces promising avenues for environmental cleanup and offers a straightforward, energy-efficient, and environmentally friendly method for producing CDs-TLFO heterojunction materials with superior photocatalytic capabilities.

Preparation of Bi2CrO6/CuO heterostructure nanocomposite to increase methylene blue decomposition under visible light irradiation

In this study, the Bi2CrO6/CuO nanocomposite was used for the photocatalytic degradation of methylene blue (MB) under visible light. Nanocomposites with different ratios (1:1, 1:2, 2:1) were synthesized under hydrothermal conditions and investigated for MB removal. Various characterization techniques, including XRD, FT-IR, FE-SEM, BET, DRS, PL, and EDS, were employed to elucidate the physicochemical aspects of the catalysts. The 2:1 nanocomposite ratio was selected as the photocatalyst with the highest removal efficiency (85 %). Four main factors, including initial concentration, solution pH, catalyst dose, and light intensity, were studied using the response surface methodology (RSM) and the Box-Behnken model. Under optimal conditions, the MB removal efficiency reached 90.06 %. Additionally, the effect of oxidizing agents (H2O2) on the enhanced removal of MB was investigated. The improved photocatalytic performance of the Bi2CrO6/CuO (2:1) nanocomposite is attributed to visible light absorption, the formation of a p-n heterostructure, efficient charge separation via the S-scheme mechanism, and increased charge carrier lifetime. Moreover, economic calculations showed that the estimated costs for the photocatalytic removal of MB from wastewater are cost-effective.

Surface Hydroxyl‐Assisted BiOBr Nanostructure Evolution for Remarkable Visible Light Photocatalytic Capability

Herein, various BiOBr nanostructures are successfully synthesized using a facile solvothermal method. A series of structural and morphological analyses clearly indicate that due to the nucleation protection provided by KOH and the presence of surface‐absorbed hydroxyl groups, BiOBr transforms from nanosheet microspheres to nanopillow aggregations (BNP) and finally to nanoneedle matrix. The open‐porous nanostructure of the BiOBr nanopillows (BNPs), along with their enhanced visible light absorption capacity and the presence of surface hydroxyls, enables them to adsorb nearly 100% of organic dyes, including rhodamine B (RhB), methylene blue, and methyl red. Furthermore, the BNP exhibits remarkable visible light photocatalytic activity, degrading higher concentrations of RhB in ≈20 min.

Oxygen Vacancy Sites Enable Efficient Photocatalytic Oxidation of Nitric Oxide: The Role of W/Mo Valence Transition in Bi2W(Mo)O6‐x

AbstractOxygen vacancy (Ov) sites play a critical role in the activation and deep oxidation of nitric oxide (NO). However, controlling the concentration and type of Ov remains a significant challenge. In this study, Bi2W(Mo)O6‐x is investigated as a model system and demonstrates that increasing the concentration of Ov substantially enhances the efficiency of air NO removal. Increasing the Ov concentrations in Bi2WO6‐x and Bi2MoO6‐x improves NO removal efficiency ≈12‐ and 11‐fold, respectively, compared to their low‐Ov counterparts. This enhancement is attributed to improved adsorption and activation of NO/O2 molecules, better separation and transfer of photogenerated carriers, and increased visible light absorption. Notably, Bi2WO6‐x remains highly stable over ten recycling tests for continuous air NO deep photooxidation, while Bi2MoO6‐x shows a 43.5% decrease in efficiency after ten runs. This sustained performance is attributed to stable Ovs without changes in metal ion valence, unlike Bi2MoO6‐x, where instability arises from the reduction of Mo6+ to Mo4+. In situ DRIFTS reveals possible pathways for the deep photooxidation of NO to nitrate (NO3−). This study provides valuable insights into designing high‐performance, durable catalysts by effectively controlling Ov concentration and type, paving the way for efficient photocatalytic air purification technologies.

Highly Elastic Full Hydrocarbon Ultralong RTP Polymers with Visible Light Excitable S0→T1 Population

AbstractHighly elastic ultralong organic room temperature phosphorescence (RTP) polymers are highly desired in wearable optoelectronic fields, but they are hardly realized in rubbers since chain segment motions deactivate triplet excitons. In the current work, it is revealed that polystyrene (PS) can inhibit triplet thermal deactivation of coronene (Cor), and it is the serious oxygen diffusion and quenching that disables RTP emission of Cor/polymers. In view of oxygen barrier function of rubbers, PS−polyisoprene−PS tri‐block elastomers (SIS) are used as Cor's doping matrices. The results show that Cor/SIS sheets show bright and ultralong afterglow with RTP lifetime up to 3.64 s in air after brief 365 nm light excitation. More impressively, Cor/SIS and its red fluorescent dye doped sheets all exhibit ultralong room temperature afterglow under large dynamic elastic deformation. Further, all these sheets exhibit long‐wave blue light excited afterglow despite Cor/SIS having no visible light absorption band, and the unique photoexcitation and emission mechanism is verified. This work not only provides the development strategy of the latest elastic RTP materials, but also will evoke a fresh understanding on organic doped RTP polymers.

AIE-derived fluorescent silsesquioxane-based hybrid aerogel for light-enhanced gold recovery

In this work, two aggregation-induced emission (AIE)-active organic fluorescent monomers (TPV, TPC) were synthesized by Knoevenagel reaction of 2,2′-([1,1′-biphenyl]-4,4′-diyl)diacetonitrile with benzaldehyde and 4-bromobenzaldehyde, respectively. Subsequently, two fluorescent hybrid porous polymers with semiconductor performance (PCS-TPV, PCS-TPC) were prepared successfully by connecting octavinyl silsesquioxane (OVS) with TPV and TPC through Friedel-Crafts reaction and Heck coupling, respectively. Among them, PCS-TPV with a hyper-crosslinked structure offered a specific surface area of up to 1165 m2 g−1; PCS-TPC was the first AIE-derived fluorescent hybrid silsesquioxane-based semiconductor polymer with 3-D conjugated structure. Compared with PCS-TPV, PCS-TPC exhibited stronger visible light absorption, higher fluorescent performance and quantum yield due to its high AIE-active unit content. Besides, PCS-TPC exhibited a remarkable gold recovery capacity (Qm = 2728 mg g−1) when exposed to visible light irradiation. Adsorption mechanism revealed that the photoelectrons produced by PCS-TPC under visible light irradiation reduced all adsorbed Au(III) to Au(I) and Au(0). Furthermore, a hybrid aerogel was prepared through physical blending of PCS-TPC with chitosan, overcoming the limitation that insoluble powder was difficult to process and recycle. This work provided a very efficient, sustainable, and industrially feasible way for gold recovery in e-waste.

Iron complexes synthesized from FeOCl with carboxylic acid based ligands as Fenton-like catalysts for the highly efficient degradation of organic dyes over a wide pH range

Iron-based materials have garnered significant attention as Fenton-like catalysts for the degradation of organic dyes. However, challenges remain in optimizing hydroxyl radical (•OH) utilization and broadening the effective pH range for practical applications. In this study, three iron-based catalysts (complex 1, 2, 3) were synthesized via a hydrothermal method, utilizing iron oxychloride (FeOCl) as the metal ion source and 4,5-imidazole dicarboxylic acid, furan-2,5-dicarboxylic acid, and 5-hydroxyisophthalic acid as ligands, respectively. The results indicate that these synthesized Fe-based catalysts exhibit enhanced visible light absorption and superior photo-Fenton activity, outperforming FeOCl in the degradation of rhodamine B (Rh-B), crystal violet (CV), and methylene blue (MB). Moreover, the Fe-based catalyst system operates effectively over a wide pH range (1–8) and efficiently degrades organic dyes. In free radical scavenging experiments, hydroxyl radicals (•OH) and superoxide radicals (•O2-) were identified as the primary agents responsible for photocatalytic degradation. Among the catalysts, complex 1 displayed notable stability, retaining its catalytic activity after three reuse cycles. This work presents a promising approach for designing highly efficient and stable Fenton-like catalysts, offering excellent environmental remediation capabilities across a broad pH range.

Plasmonic Nanocomposite for Visible Light‐Modulated Bimorph‐Actuator

AbstractSoft actuators have great potential applications in sophisticated movement and sensitive devices due to their flexible nature, good interaction, and precise control. However, existing carbon‐based optical actuators are limited in their response under visible light irradiation. The limited visible light absorbance of the carbon nanostructure brought the metallic nanoparticle into the soft actuators that can absorb visible light. This study introduces a new type of plasmonic photothermal‐bimorph actuator, using graphene oxide (GO), reduced graphene oxide (rGO), and silver nanorods (Ag NRs) to overcome the limitations of traditional optical actuators. The bimorph film is actuated by visible and near‐infrared light stimuli with various power densities showing reversible deformation behavior. The actuator shows significant bending associated with a ≈50° change in bending angle under visible light irradiation with a response time of ≈5 ± 1 sec. Furthermore, a smart photo‐controlled non‐contact switch is fabricated based on photo‐thermal conversion properties, demonstrating perfect integration of plasmonic bimorph actuators. The density functional theory based molecular dynamics calculations provide an additional understanding of the bending of actuators under external stimulus. Using illustrative demonstrations of actuators, these results hint at a method for generating multipurpose visible light‐based soft robots, supporting a new approach to developing an optical locking system.

Synthesis and Binding Properties of High-Affinity Histidine-Bearing Polymers for Wood Lignin.

The pursuit of molecules capable of binding to wood lignin is pivotal for advancing lignin degradation technology, particularly when combined with lignin degradation catalysts. In this study, synthetic polymers bearing histidine moieties, demonstrating remarkable affinity for wood lignin are reported. These polymers, featuring varying degrees of histidine substitution in the form of histidine methyl esters, are synthesized through controlled radical polymerization of an activated ester-bearing monomer, employing a fluorescein-labeled chain transfer agent and subsequent postpolymerization amidation with histidine methyl ester. The binding properties of these histidine-bearing polymers with milled wood lignin under aqueous conditions are investigated. Qualitative assessment of lignin-binding capabilities involve spectroscopic analysis of changes in absorbance of visible light and fluorescence intensity. Furthermore, quantitative evaluation is conducted through surface plasmon resonance measurements to determine the binding parameters of the polymers with wood lignin. Notably, polymers with higher histidine substitution exhibit enhanced binding affinity compared to those with lower histidine substitution levels.

Computational screening of 2D ternary penta-materials with auxetic properties and efficient photocatalytic CO2 reduction

Due to unique structural and electronic properties, pentagon-based two-dimensional (2D) materials have captured significant interest in recent years. However, previous studies on these materials have primarily focused on unary and binary systems, with less exploration of ternary pentagonal structures. Herein, we conducted first-principles calculations to evaluate the stability of 122 ternary pentagonal monolayers composed of metals, nitrogen, and chalcogen. We identify six highly stable candidates, including AuNS, CuNTe, GaNS, InNS, SbNS, and SbNSe that meet the criteria for thermodynamic, mechanical, and dynamic stability. Mechanical property analysis reveals that five of these monolayers demonstrate auxetic behavior. Electronic structure calculations show that all candidates are semiconductors with band gaps ranging from 0.12 to 3.42 eV. Specifically, the SbNS and SbNSe monolayers are indirect semiconductors with band gaps of 2.25 and 2.27 eV, respectively. These materials exhibit strong visible light absorption, and potentially serve as exceptional photocatalysts for the reduction of CO2 to CH4 due to the optimal band alignment. The free energy change in the rate-limiting step is even lower than those found in g-C3N4 and MoS2-based systems. Our findings highlight new pentagon-based 2D materials with remarkable electronic, mechanical, and optical properties, making them promising candidates for applications in mechanics and energy conversion.

Photocatalyst for Antibiotics Degradation by In Situ Growth of Direct Z-Type Bi2S3/Bi4Ti3O12 Heterojunction.

Effective removal of antibiotics from aqueous solutions has emerged as a hot research topic in wastewater treatment. Photocatalytic degradation of antibiotics is one of the most effective methods to reduce ecological damage and environmental pollution. In this work, a novel photocatalyst consisting of Z-type heterojunction Bi2S3/Bi4Ti3O12 (BS/BTO) with visible light responses was prepared by an in situ growth method, and the obtained material was used for the degradation of tetracycline hydrochloride (TC). The best performing photocatalyst was BS/BTO-2, which exhibited high photocatalytic activity. The rates of TC degradation reached 97.9% within 40 min of illumination. The photocatalyst demonstrated a high stability and reproducibility even after 5 cycles. Electron spin resonance (EPR) tests and quenching experiments established that ·O2- and h+ were the main species responsible for the elimination of TC. On the basis of theoretical calculations and experimental data, a possible mechanism for the photocatalytic degradation of TC has been proposed. The heterojunction structure, which effectively increases the visible light absorption range and decreases the compounding efficiency of photogenerated electrons and holes, is principally responsible for the photocatalytic performance of BS/BTO. Additionally, liquid chromatography-mass spectrometry (LC-MS) was utilized to investigate the formation and degradation of reaction intermediates. The nontoxicity of the solution after tetracycline degradation was verified by cultivating wheat seeds. This work offers guidance for bismuth-based photocatalysts in the field of sustainable wastewater treatments.

A robust floating oxygen-doped graphitic carbon nitride sheet for efficient photocatalytic CO2 conversion

Photocatalytic CO2 reduction offers a promising approach for converting CO2 into valuable chemicals. However, typical conversion systems suffer from inefficient CO2 mass transfer and complex recycling processes. In this study, we developed a floating sheet as a robust photocatalytic CO2 conversion system by integrating graphitic carbon nitride (CN) nanosheets onto polytetrafluoroethylene (PTFE) fiber membrane, followed by oxygen (O) doping into the CN (CN-O) via oxygen-plasma treatment. The floatable CN-O/PTFE sheet exhibits slight wettability in water under 0.25 MPa of CO2 pressure in our reactor system, facilitating the delivery of dissolved CO2 to the CN-O photocatalyst surface. O-doping enhances the visible light absorption and improves the separation and transport efficiency of photogenerated electrons and holes due to O-doping-induced states in CN. Consequently, the floating CN-O/PTFE system achieves an exceptional photocatalytic CO2 conversion rate of 102.3 μmol g-1h−1, approximately 4.8 times higher than a conventional CN-powder dispersion system in water. Moreover, the sheet demonstrates excellent cycling durability, with no significant exfoliation of the catalytic layer or reduction in CO2 photoreduction activity after 20 consecutive cycles. This study presents a novel approach to designing photocatalytic systems for efficient CO2 conversion.

A sustainable pathway for the photodegradation of Rhodamine B dye using Mn-doped CaFe2O4 anchored on citrus fruit peel-derived biochar matrix

This report details the synthesis of Mn-doped CaFe2O4 nanoparticles supported on biochar. We evaluate the photocatalytic activity of the resulting nanocomposite towards the degradation of Rhodamine B (RhB) dye, a well-known environmental pollutant. Doping CaFe2O4 with Mn and subsequently incorporating it onto biochar results in enhanced visible light absorption and diminished photoluminescence (PL) intensity. The photocatalyst Mn-doped CaFe2O4/Biochar was synthesized via a hydrothermal method. The morphology and photocatalytic characteristics of the synthesized catalyst were comprehensively scrutinized through powder X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), transmission electron microscopy (TEM), ultraviolet–visible diffuse reflectance spectroscopy (UV-DRS), and photoluminescence (PL) investigations. The photocatalytic properties of the catalyst were further assessed through the degradation of RhB dye, revealing a degradation efficiency of 97.31% within a 70-minute timeframe. The photocatalyst exhibits reusability for up to five cycles while maintaining a photocatalytic efficiency of more than 80%.

Theoretical design of Z-scheme photocatalyst for water splitting with excellent catalytic performance: GeSe/PtS2 heterojunction

In the face of the urgent need for energy transition, Z-scheme heterojunctions are considered highly suitable candidates for future photocatalytic applications, owing to their exceptional optoelectronic characteristics and high catalytic efficiency. This paper systematically investigates the geometric structure, optoelectronic properties, and catalytic efficiency of the GeSe/PtS2 heterojunction through detailed first-principles calculations. The findings indicate that the band structure of the GeSe/PtS2 heterojunction presents a staggered Type-Ⅱ band alignment and exhibits an indirect band gap measuring 1.75 eV. Charge transfer analysis reveals that under the interplay of an intrinsic electric field directed from GeSe to PtS2 and the band bending occurring at the heterojunction interface, the GeSe/PtS2 heterojunction conforms to the obvious Z-scheme electron transfer mechanism characteristics. This facilitates the hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) to proceed smoothly on opposite sides of the heterojunction. Across the pH range of 0 to 14, the heterojunction's band edge positions successfully span the redox potentials of water, and can still meet the hydrolysis potential requirements under strain. In addition, the GeSe/PtS2 heterojunction not only effectively compensates for the poor absorption of PtS2 monolayer to visible light, but also achieves a wider visible light absorption range through the strain-induced redshift in the spectrum. At the same time, the solar to hydrogen (STH) efficiency of up to 15.56% further underscores the substantial catalytic potential of the GeSe/PtS2 heterojunction, offering promising design strategies for a technological revolution in the field of photocatalysis.

A comparative study of BiFeO3-based compounds for enhanced hydrogen evolution reaction

We present a comprehensive study, combining experimental and theoretical approaches, to assess the hydrogen evolution reaction (HER) efficiency of BiFeO3-based solid solutions. Initially, we investigate the electronic and optical properties of these compounds, with a particular focus on band edge alignment relative to water redox potentials. Our findings show that the materials exhibit optimal band gaps of approximately 2.0 eV, indicative of enhanced visible light absorption and favorable energetic alignment to drive efficient hydrogen generation. To corroborate our theoretical predictions, we perform photoelectrochemical measurements on selected BiFeO3-based compounds synthesized via the solid-state method. Our experimental results reveal a high hydrogen yield, with BiFeO3-SrTiO3 achieving a production rate of ∼114 µmol/L in 30 min, outperforming BiFeO3-BaTiO3 (∼70 µmol/L) and pristine BiFeO3 (∼61 µmol/L). These findings validate our theoretical assumptions and demonstrate the superior HER performance of BiFeO3-SrTiO3, positioning it as a highly promising candidate for sustainable hydrogen production.

Porphyrin-prompted Robust Leadfree Cesium Bismuth Bromide for Efficiently Photodegrading Antibiotics Pollutants in Water

The lead-free halide perovskite represented by Cs3Bi2Br9 (CBB) has attracted intense attention as an environmentally friendly alternative for toxic lead halide perovskite (CsPbBr3). However, the limited light absorption and instability of Cs3Bi2Br9 hinder its practical application in photocatalysis. In this work, Cs3Bi2Br9 nanosheets was modified with bifunctional porphyrin (CBB-TCPP) displayed enhanced visible light absorption properties and promising water stability. The CBB-0.5TCPP shows a sharply improved photodegradation performance of 84% in 60min in water and demonstrating the outstanding cycling stability. Furthermore, photoelectrochemical tests suggested that the charge separation and transfer properties of the modified perovskite materials were significantly improved compared with the pristine CBB. The CBB-0.5TCPP exhibited an impressive photogenerated carrier separation efficiency of 90.74%. This work innovatively proposes a new way to modify perovskite with double duty by boosting stability and optimizing light absorption properties.

In Situ Self-Inflating-Modeled Giant-Vesicle-Like Quantum Dot Assembly for Biomimetic Artificial Photosynthesis.

The study of biomimetic self-assembly is crucial for scientists aiming to understand the origin of life and construct biomimetic functional structures. In our endeavor to create a biomimetic photosynthetic assembly, we discover a self-inflation behavior that drives the components, MPA-CdSe quantum dots (QDs) and a solid cationic polyelectrolyte, CPPA, to form a giant-vesicle-like (GVL) architecture, termed GVL-QDs@CPPA. The in situ generation of osmotic pressure during the self-assembly of QDs onto swollen CPPA in water was found to cause this self-inflation process. The resulting vesicle-like structure exhibits spatial characteristics similar to those of natural photosynthetic cells, with QDs acting as pigments uniformly distributed on the CPPA membranes, which have embedded cobalt catalytic centers. This architecture ensures optimal absorption of visible light and facilitates efficient electron transfer between the QDs and catalytic centers. As a result, GVL-QDs@CPPA assemblies efficiently harness photogenerated electrons and holes to convert protons and isopropanol into hydrogen (H2) and acetone, respectively, achieving a nearly 1:1 ratio of the reduction product (H2) to the oxidation product (acetone).

Colloidal Quantum Dots‐Based Photoelectrochemical‐Type Optoelectronic Synapse

AbstractCurrent artificial neuromorphic systems are mainly constructed using solid‐state optoelectronic synaptic devices, limiting their potential artificial intelligence applications in liquid medium. Here, colloidal CuInGaSe/ZnSe quantum dots (QDs) with environment‐benign feature and broad visible light absorption are prepared to fabricate a photoelectrochemical (PEC)‐type optoelectronic synaptic device operating in aqueous electrolyte, enabling unique biological synaptic behaviors including paired‐pulse facilitation (PPF), short‐term plasticity (STP), long‐term plasticity (LTP) and learning‐forgetting‐relearning process when simulated by optical pulses with various wavelength, pulse number, frequency, power density, and applied voltage. These results demonstrate the feasibility of building PEC‐type optoelectronic synapses using colloidal QDs, paving the way to realize available optoelectronic synaptic devices for prospective underwater artificial intelligence technology.

Modulation of the Microstructure and Enhancement of the Photocatalytic Performance of g-C3N4 by Thermal Exfoliation

This work explores the impact of reaction temperature during thermal exfoliation treatment of bulk-g-C3N4 in the air atmosphere on the structure and performance of the resulting CN photocatalyst. The analysis conducted using XRD, FT-IR, XPS, SEM, and elements mapping tests, illustrated an increase in nitrogen-vacancy and oxygen content on the surface of the CN photocatalyst, resulting in a porous and sparse structure, changes in crystal size, and improved visible light absorption performance. The photocatalytic reduction experiments of hexavalent chromium (Cr(VI)) showed that the CN-540 showed the highest reduction rate of 96.9%, with a reaction rate constant 6.21 times that of bulk-g-C3N4. After 100 min of illumination, the photocatalytic degradation rates of CN-540 for TC-HCl and RhB were 66.7% and 60.6%, respectively. The TOC test results indicated mineralization rates of 51.5% for TC-HCl and 46.6% for RhB. Room temperature fluorescence spectroscopy (PL), transient photocurrent response (TPC), and electrochemical impedance spectroscopy (EIS) measurements confirmed the excellent photogenerated charge carrier separation and transport efficiency of CN-540. The photocatalytic mechanism for reducing Cr(VI) by CN-540 was elucidated based on the active species •OH and •O2– and Mott-Schottky (M-S) tests. This study provides experimental data for optimizing the photocatalytic performance of g-C3N4 and paves a new way for developing efficient photocatalysts. Copyright © 2024 by Authors, Published by BCREC Publishing Group. This is an open access article under the CC BY-SA License (https://creativecommons.org/licenses/by-sa/4.0).