Heterogeneous Photocatalysis Research Articles

Nanostructured Magnetite Coated with BiOI Semiconductor: Readiness Level in Advanced Solar Photocatalytic Applications for the Remediation of Phenolic Compounds in Wastewater from the Wine and Pisco Industry

Heterogeneous photocatalysis is an advanced, efficient oxidation process that uses solar energy to be sustainable and low-cost compared to conventional wastewater treatments. This study synthesized BiOI/Fe3O4 using the solvothermal technique, evaluating stoichiometric ratios of Bi/Fe (2:1, 3:1, 5:1, and 7:1) under simulated solar irradiation to optimize the degradation of caffeic acid, a pollutant found in wastewater from the wine and pisco industry. The nanomaterial with a 5:1 ratio (BF-5) was the most effective, achieving a degradation of 77.2% in 180 min. Characterization by X-ray Diffraction (XRD), Transmission Electron Microscopy (TEM), Brunauer–Emmett–Teller (BET), Barrett–Joyner–Halenda (BJH), Fourier Transform Infrared Spectroscopy (FTIR), Diffuse Reflectance Spectroscopy (DRS), and Vibrating Sample Magnetometry (VSM) showed that BF-5 has a porous three-dimensional structure with BiOI nanosheets coating the Fe3O4 surface, while retaining the pristine BiOI properties. The magnetite provided magnetic properties that facilitated the recovery of the photocatalyst, reaching 89.4% recovery. These findings highlight the potential of BF-5 as an efficient and recoverable photocatalyst for industrial applications. The technical, economic, and environmental feasibility were also evaluated at the technological readiness level (TRL) to project solar photocatalysis in real applications.

Visible‐Light‐Mediated Selective Fluorine Incorporation by Anthraquinone‐Based Covalent Organic Framework as Recyclable Photocatalyst

Covalent organic frameworks (COFs) serve as an excellent foundation for heterogeneous photocatalysis. Herein, we synthesized an anthraquinone‐based COF (TpAQ) on a gram scale via a mechanochemical grinding pathway. This COF was employed as a visible‐light‐harvesting photocatalyst for selective fluorination of benzylic C‐H bonds and perfluoroalkylation of arenes. The carbonyl core in the anthraquinone linker facilitated benzylic fluorination through a hydrogen atom transfer (HAT) pathway. Control experiments and photophysical analysis were conducted to gain deeper insight into the reaction mechanism. The recyclability up to 5th cycle without significant loss of the yield (> 90%) highlighted the robustness of the catalyst. This reaction strategy was also executed on a gram scale to validate the scalability of the protocol.

Carbazole and Triazine-Based D-A Covalent Organic Framework for Visible Light-Mediated Photocatalytic C-H Activation of Imidazopyridine and Indole.

Two-dimensional donor-acceptor covalent organic frameworks (COFs) show considerable promise for metal-free and heterogeneous photocatalysis due to their efficient charge carrier separation and exciton transport upon photoexcitation. To date, numerous photocatalysts have been developed. However, they encounter several challenges, such as inadequate sunlight harvesting ability, poor photostability, and nonreusability. Fortunately, the emergence of COFs presents a promising solution to these problems. Herein, we report an imine-linked CzTA-TAPT COF featuring carbazole as the electron donor and triazine as the electron acceptor. Compared to the previously reported C2-linker-derived CzDA-TAPT COF, this C3-linked COF exhibits good charge separation and charge carrier transport. As a consequence, it demonstrates excellent photocatalytic applicability in the C-3 thiocyanation of imidazo[1,2-a]pyridine and indole under ambient conditions under visible light. Moreover, its broad substrate compatibility and high recyclability provide a green and sustainable approach for the thiocyanation of imidazopyridine and indole. To the best of our knowledge, this is the first heterogeneous catalyst demonstrated for the thiocyanation of imidazo[1,2-a]pyridine. These findings will inspire further research in the development of high-performance D-A COFs as photocatalysts for organic transformations.

Visible Light Excitation of Poly-(para-Phenylene Ethynylene) Enables Heterogeneous Photocatalytic Oxidations of Amines in Flow.

Heterogeneous visible light photocatalysis is a compelling approach to address sustainability in synthetic photochemistry. However, the use of solid-state photocatalysts remains very unpopular in organic synthesis because of their limited accessibility and the black-box effect associated to the lack of rational between their molecular structure and their photochemical properties. Herein, we disclose the synthesis, characterization, photocatalytic properties and synthetic applications of a simple and readily available solid-state conjugated organic polymer, poly-(para-phenylene ethynylene) 1, which exhibits a strong oxidative power upon irradiation with visible light (E(1*/1•-) = +1.67 V vs SCE). Comparisons with structural analogues highlighted the superior photocatalytic activity of this linear semiconductor, on account of its fully conjugated architecture. The associated excited-state reactivity enabled the transformation of various amines into imines in batch and continuous flow reactors together with straightforward photocatalyst recycling. Mechanistic investigations revealed concomitant photoredox and energy transfer pathways, that led to the formation of the desired products. Ultimately, the inline generation of imines was exploited in telescoped three-component Ugi reactions (3CR) in batch and flow toward biologically relevant α-acylaminoamides.

Visible Light Excitation of Poly‐(para‐Phenylene Ethynylene) Enables Heterogeneous Photocatalytic Oxidations of Amines in Flow.

Heterogeneous visible light photocatalysis is a compelling approach to address sustainability in synthetic photochemistry. However, the use of solid‐state photocatalysts remains very unpopular in organic synthesis because of their limited accessibility and the black‐box effect associated to the lack of rational between their molecular structure and their photochemical properties. Herein, we disclose the synthesis, characterization, photocatalytic properties and synthetic applications of a simple and readily available solid‐state conjugated organic polymer, poly‐(para‐phenylene ethynylene) 1, which exhibits a strong oxidative power upon irradiation with visible light (E(1*/1•–) = +1.67 V vs SCE). Comparisons with structural analogues highlighted the superior photocatalytic activity of this linear semiconductor, on account of its fully conjugated architecture. The associated excited‐state reactivity enabled the transformation of various amines into imines in batch and continuous flow reactors together with straightforward photocatalyst recycling. Mechanistic investigations revealed concomitant photoredox and energy transfer pathways, that led to the formation of the desired products. Ultimately, the inline generation of imines was exploited in telescoped three‐component Ugi reactions (3CR) in batch and flow toward biologically relevant α‐acylaminoamides.

A Combination of Adsorption and Photocatalysis Processes for the Removal of Direct Blue 71 (DB71) Dye on Fe-Doped Layered Double Hydroxides

Pollution in ecosystems has increased, especially in water, due to the pollutant agents that alter their chemical, physical and biological characteristics. This requires actions to resolve or at least reduce the harmful effects generated on the environment and people’s health. Many of the contaminants present in water come from the industrial sector, with the textile industry being one of the most impactful as it uses mostly synthetic dyes, which are characterized as being recalcitrant and toxic, so they cannot be degraded by conventional water treatment methods. Advanced oxidation processes have a great potential for application, especially those that use heterogeneous photocatalysis. The present research evaluates the efficiency in the adsorption and degradation of the triazoic Direct Blue 71 dye in aqueous mediums at concentrations of 600 ppm by the heterogeneous photocatalysis method. The photocatalysts used are layered double hydroxides (LDHs) with a Mg/Al = 3 ratio and are thermally activated and doped with Fe at 1, 3 and 5% w/w. The most efficient materials achieved removal percentages greater than 80% by means of a second-order kinetic model with a DB71 half-life decolorization of less than one hour; as shown by an HPLC study, the absence of intermediate products would confirm the mineralization of the dye.

Evaluation of the acute phytotoxicity of phototreated textile effluent using cucumber (Cucumis sativus) and radish seeds (Raphanus sativus)

Water, as a vital resource, plays a crucial role in human activities, notably in the textile industry, whose operations can significantly impact the quality of this resource. It is imperative to explore solutions, such as the adoption of advanced oxidative processes, which encompass the degradation of dyes present in effluents through the action of hydroxyl radicals. To evaluate the effectiveness of this treatment, acute phytotoxicity tests are carried out to analyze the responses of plant organisms to the effluents. Therefore, this study aimed to assess the acute phytotoxicity of a natural textile effluent subjected to heterogeneous photocatalysis and homogeneous photo-fenton treatments. Acute phytotoxicity tests were performed with cucumber (Cucumis sativus) and radish (Raphanus sativus) seeds, both for the treated effluent and in natura. The results revealed a sensitivity of cucumber seeds to effluent in natura and resistance to radish seeds. Regarding the phototreated effluents, the results showed an increase in seed germination rate and contributed to enhance this germination. Phytotoxic tests were also carried out with sodium chloride and sodium sulfate, and the toxicity of these substances to cucumber and radish seeds was confirmed.

Advanced Oxidation Technology Using Fe0/H2O2 as an effective treatment for recycling industrial wastewater for irrigation of Lolium perenne crops.

This study focused on developing a new Phenton treatment of water effluent coming from a local industrial estate and staining industry site. Different advanced oxidation technologies (AOTs) such as heterogeneous photocatalysis, Photo-Fenton and UV-Vis/H2O2 using FeSO4, and pure iron were evaluated. To develop this study, water samples were tested before and after each treatment. In general, after AOTs the amount of chlorides, nitrates, hydrocarbons, heavy metals, TOC and bacteria significantly decreased. Photo-Fenton and UV-Vis/H2O2/TiO2 showed the best performance in the treatment of staining industry and industrial wastewater, respectively. Photo-Fenton mineralized 100% of dyes, reduced by 99% total coliforms, eliminated 76% of TOC and 60% of heavy metals tested. Interestingly, use of iron metal in the Photo-Fenton treatment was found to achieve similar results. This means wastewater can be treated with benign chemicals. Treated wastewater was evaluated as a potential water source for the irrigation of Lolium perenne, a conventional crop in animal feed. In general, the physical characteristics of Lolium perenne such as leaf and roof length and width, were not significantly modified after irrigation with treated wastewater. Similar results were obtained using treated tap water as reference. A trace number of metals remaining from treatment was detected in grass and soil. However, the concentration of Cd, Cr, Cu, and Zn was very similar to tap water. Considering these outcomes, use of non-toxic zero valent iron metal and hydrogen peroxide in a Photo-Fenton reaction is a pilot plant scalable alternative oxidating treatment technology for recycling industrial wastewater in agricultural activities.Top of Form

Photocatalytic degradation of propranolol hydrochloride in aqueous medium employing bentonite-TiO2 nanocomposites

Propranolol hydrochloride, a widely used medication, contaminates water bodies as it’s not fully metabolized by humans. Conventional water treatment methods are ineffective against it, necessitating more advanced approaches like heterogeneous photocatalysis. TiO2, often used as a photocatalyst, is typically combined with other materials to form nanocomposites, enhancing its activity. This study evaluated TiO2 synthesized via sol–gel method with organophilized bentonite for propranolol removal. Composites were prepared through solvothermal treatment, and an experimental design assessed the TiO2/bentonite ratio, time, and temperature of the solvothermal treatment effects on photocatalytic activity. Increasing these parameters led to a nanocomposite capable of removing over 99 % of propranolol in water after 60 min of adsorption followed by 150 min of photocatalysis. The nanocomposite remained active after four treatment cycles. Characterization revealed TiO2 (anatase) nanoparticles with a size range of 6–13 nm dispersed in bentonite’s fine tubular structures. This research underscores the potential of TiO2-based nanocomposites in addressing pharmaceutical contamination in water bodies efficiently.

Enhanced degradation of venlafaxine induced by Fe2O3/CeO2 heterostructures through the thermal transformation from type I to direct Z-scheme in heterogeneous photo-Fenton

Heterostructures based on Fe2O3/CeO2 were synthesized by coprecipitating iron and cerium salts, with 70 % and 50 % atomic percentage of iron, and heat treatment at 600 and 800 °C (Fe70Ce600, Fe50Ce600, Fe70Ce800, Fe50Ce800). The catalytic activity in the Fenton and photo-Fenton process was evaluated in the degradation of venlafaxine (VEN) using UV/Vis LEDs. Treatment at 800 °C promoted greater crystallinity, increased crystallite size, decreased specific area, and high absorption between 200 and 600 nm, and bandgap energy (Eg) between 1.6 and 3.0 eV were observed. The heat treatment promoted different mechanisms in heterostructure materials with type I (straddling) schemes for Fe70Ce600 and Fe50Ce600, type II for Fe50Ce800, and direct Z for Fe70Ce800 responsible for generating a higher concentration of HO• radicals, high oxidation-reduction power (Fe2+/Fe3+) and (Ce4+/Ce3+), greater effective separation of charge carriers, providing improved catalytic activity due to the synergy between heterogeneous photocatalysis and photo-Fenton processes. LC-MS/MS analysis identified 12 transformation products (TPs), involving hydroxylation reactions, demethylation, and loss of cyclohexanol. The transformation products TP2 and TP9 were exclusive to Fe70Ce800, confirming different mechanisms among the heterostructures.

Single-Atom Electron Pumps Over Transition Metal Chalcogenides Boosting Photocatalysis.

Cocatalyst is of paramount significance to provide fruitful active sites for suppressing the spatial charge recombination toward boosted photocatalysis. Up to date, exploration of robust and stable cocatalysts is remained challenging. Inspired by the intrinsic merits of single-atom catalysts (SACs), such as distinctive electronic structure and high atomic utilization efficiency, single-atom/transition metal chalcogenides (TMCs) is utilized as a model to synthesize CdS-Pd single-atom catalyst (CdS-PdSA) heterostructures. This demonstrates the precise anchoring of isolated metal single-atom catalysts (SACs) onto TMCs through a simple yet effective wet-chemical strategy. The resulting heterostructures exhibit significantly enhanced and stable photocatalytic activity for selective anaerobic organic transformations and hydrogen production under visible light. This enhancement is primarily inferred due to the role of Pd SACs as electron pumps, which directionally trap the electrons photoexcited over CdS, accelerating the spatial charge separation and prolonging the carrier lifespan. The charge transport route and photocatalytic mechanism are elucidated. This work underscores the potential of SACs as cocatalysts in heterogeneous photocatalysis, offering valuable insights for the rational design of atomic-level cocatalysts for solar-to-chemical energy conversion and beyond.

In‐situ Monitoring of Photocatalysis on Polymeric Carbon Nitride Thin Films

Polymeric carbon nitride has attracted significant interest in heterogeneous photocatalysis due to its activity under visible‐light irradiation. Herein, we report on using carbon nitride‐coated NMR tubes for in‐situ studies of photocatalytic reaction mechanisms. In a first step, we exploited carbon nitride‐coated crimp vials as batch photoreactors for visible photocatalytic fluorinations of unactivated C(sp3)‐H bonds, with moderate to excellent yields and reusability over multiple cycles. Eventually, carbon nitride‐coated NMR tubes were used as a photoreactor by coupling them with optical fiber irradiation directly inside the spectrometer. This enabled us to follow the reaction with in‐situ NMR spectroscopy identifying reactive intermediates otherwise elusive in conventional analyses. The method provides advantages for the study of photocatalytic mechanisms of complex reactions and substantially reduces the need of comparative tests for depicting reaction intermediates and conversion pathways.

In-situ Monitoring of Photocatalysis on Polymeric Carbon Nitride Thin Films.

Polymeric carbon nitride has attracted significant interest in heterogeneous photocatalysis due to its activity under visible-light irradiation. Herein, we report on using carbon nitride-coated NMR tubes for in-situ studies of photocatalytic reaction mechanisms. In a first step, we exploited carbon nitride-coated crimp vials as batch photoreactors for visible photocatalytic fluorinations of unactivated C(sp3)-H bonds, with moderate to excellent yields and reusability over multiple cycles. Eventually, carbon nitride-coated NMR tubes were used as a photoreactor by coupling them with optical fiber irradiation directly inside the spectrometer. This enabled us to follow the reaction with in-situ NMR spectroscopy identifying reactive intermediates otherwise elusive in conventional analyses. The method provides advantages for the study of photocatalytic mechanisms of complex reactions and substantially reduces the need of comparative tests for depicting reaction intermediates and conversion pathways.

Accessing monomers from lignin through carbon-carbon bond cleavage.

Lignin, the heterogeneous aromatic macromolecule found in the cell walls of vascular plants, is an abundant feedstock for the production of biochemicals and biofuels. Many valorization schemes rely on lignin depolymerization, with decades of research focused on accessing monomers through C-O bond cleavage, given the abundance of β-O-4 bonds in lignin and the large number of available C-O bond cleavage strategies. Monomer yields are, however, invariably lower than desired, owing to the presence of recalcitrant C-C bonds whose selective cleavage remains a major challenge in catalysis. In this Review, we highlight lignin C-C cleavage reactions, including those of linkages arising from biosynthesis (β-1, β-5, β-β and 5-5) and industrial processing (5-CH2-5 and α-5). We examine multiple approaches to C-C cleavage, including homogeneous and heterogeneous catalysis, photocatalysis and biocatalysis, to identify promising strategies for further research and provide guidelines for definitive measurements of lignin C-C bond cleavage.

Light harvesting S-scheme g-C3N4/TiO2/M photocatalysts for efficient removal of hazardous moxifloxacin

The development of advanced photocatalysts with enhanced efficiency for environmental remediation is critical for addressing persistent organic pollutants like Moxifloxacin. In this study, we present a novel S-scheme heterojunction g-C3N4/TiO2/M photocatalyst designed to optimize light harvesting and charge separation for the effective degradation of Moxifloxacin. The innovative S-scheme configuration enables superior charge transfer dynamics by retaining potent photogenerated electrons in the conduction band of TiO2 and holes in the valence band of g-C3N4, significantly improving photocatalytic performance compared to conventional Type-II systems. Heterogeneous photocatalysis, particularly using TiO2-based materials, offers a promising approach. Here, we synthesized TiO2 hybridized with metal-doped g-C3N4 (GCNTM) via a simple hydrothermal method. The fabricated nanocomposites were characterized using SEM, XRD, FTIR, and UV–Vis (DRS). These GCNTM nanocomposites were employed for the degradation of hazardous Moxifloxacin (MXF) under visible light. Detailed analysis of the photocatalytic mechanism reveals that the synergistic interaction between g-C3N4, TiO2, and the co-catalyst M not only broadens the light absorption spectrum but also enhances the separation and lifespan of charge carriers. Among the synthesized materials, GCNTLa demonstrated the highest degradation efficiency, achieving 96 % removal of MXF. This enhanced activity is attributed to the effective suppression of charge recombination, leading to the generation of reactive species responsible for MXF degradation. Additionally, GCNTM showed remarkable stability and reusability, with only a 6 % reduction in efficiency after five cycles, confirming its high reusability and mechanical stability. Our S-scheme photocatalyst demonstrates a marked increase in the degradation rate of Moxifloxacin under visible light irradiation, highlighting its potential for practical environmental applications.

A Porphyrin-Based sp2 Carbon-Conjugated covalent organic polymer containing flexible chains for efficient heterogeneous photocatalysis

Porphyrin based covalent organic polymers are excellent catalysts. Herein, a sp2 carbon linked porphyrin based organic polymer H2Pp-PDAN was designed and synthesized by co-condensation of porphyrin monomer containing flexible chains H2Pp with 1, 4-phenylenediacetonitrile PDAN. As photocatalysts, H2Pp-PDAN exhibited excellent photocatalytic performance for photocatalytic oxidative coupling of amines, and was successfully used for 15 consecutive reactions with no detectable reduction of the catalytic activity. H2Pp-PDAN showed good photocatalytic activity and excellent recyclability for photocatalytic oxidation of thioanisole to methyl phenyl sulfoxide. Mechanistic studies revealed that the photocatalytic oxidation of benzylamine coupling by H2Pp-PDAN proceeds via both energy transfer and electron transfer pathways.

Ce-doped ZnO nanonails synthesized by a simple thermal evaporation method for photocatalytic degradation

One-dimensional (1D) nanomaterials have garnered significant scientific and technological attention due to their potential applications in electronics devices, gas sensing, energy conversion, and photocatalysis. However, the development of a simple and low-cost technique for 1D nanostructure synthesis remains a challenge. The doping of ZnO nanostructures has proven to be an effective way to improve their internal properties. In this work, one-dimensional ZnO and Ce-doped ZnO nanorods and nanonails were synthesized by a simple thermal evaporation method using different weight ratios of ZnS and CeO2 precursor powders in a catalyst-free process. The effects of cerium doping concentration on the structural, morphological, and optical properties of the as-prepared samples were investigated. XRD analysis confirmed that the crystal structure was converted from the cubic ZnS phase to the hexagonal ZnO phase with increasing annealing temperatures. The UV–Vis spectra showed that the optical absorption edge of Ce-doped ZnO samples was slightly red-shifted. Additionally, the band gap energy decreases with increasing cerium concentration. SEM images showed that the morphology of the structures obtained changed from nanorods to nanonails as the Ce content increased. The incorporation of Ce ions into the ZnO matrix has been successfully confirmed by HRTEM, Raman, and EDX analysis. Photocatalytic activity studies showed that Ce-doped ZnO samples exhibited significantly enhanced photocatalytic performance compared to pure ZnO for the degradation of rhodamine B under UV radiation. These results may suggest the use of heterogeneous photocatalysis as an efficient, cheap, and environment-friendly alternative for the removal of pollutants from water and the use of Ce-doped ZnO as a promising candidate.

Ag doped TiO2 anchored on metal free g-C3N4 for enhanced solar light activated photodegradation of a dye

Heterogeneous semiconductor photocatalysis has attracted researcher's attention in wastewater treatment owing to the improved surface area, optical properties, and charge transfer rate for boosted degradation of organic pollutants. Thus, the g-C3N4/Ag/TiO2 was prepared following a hydrothermal route for the degradation of azo dye tartrazine (TA) used as a food colourant under solar light. Before application, the composite and pristine materials were interrogated for physicochemical and structural properties using SEM, TEM, EDS, XPS, XRD, UV–vis DRS, PL, BET, Raman, and FTIR spectroscopy. The PL and electrochemical analysis revealed that the CNAT composite had a high charge transfer rate that was coupled with low charge carrier complexation. The degradation efficiency of 91 % was realized in 180 min and the rate of pseudo-first-order kinetics of 0.01143 min−1 was obtained. The CNAT catalyst also displayed high removal efficiency towards a cocktail of naproxen (NPX) and TA. The improved removal efficiencies stem from increased visible usage, reduced charge carrier compounding, and formation of Z-scheme heterojunction with high redox capabilities. The total organic carbon removal reached 95 % while CNAT showed high convincing stability even after four cycles. Given the above results, the hydrothermally prepared composite catalyst can be extended to other organic pollutants such as pharmaceuticals, pesticides, and reduction of inorganics.

Degradation of Organic Dye Congo Red by Heterogeneous Solar Photocatalysis with Bi2S3, Bi2S3/TiO2, and Bi2S3/ZnO Thin Films

In this work, bismuth sulfide (Bi2S3) thin films were deposited by a chemical bath deposition (CBD) technique (called soft chemistry), while titanium dioxide (TiO2) nanoparticles were synthesized by sol–gel and zinc oxide (ZnO) nanoparticles were extracted from alkaline batteries. The resulting nanoparticles were then deposited on the Bi2S3 thin films by spin coating at 1000 rpm for 60 s each layer to create heterojunctions of Bi2S3/ZnO and Bi2S3/TiO2. These materials were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), and energy dispersive X-ray spectroscopy (EDX). The optical and contact angle analyses were undertaken by UV–Vis spectroscopy and a contact microscopy angle meter, respectively. The calculated band gap values were found to be between 1.9 eV and 2.45 eV. The Bi2S3 presented an orthorhombic structure, the TiO2 nanoparticles presented an anatase structure, and the ZnO nanoparticles presented a wurtzite hexagonal crystal structure. Furthermore, heterogeneous solar photocatalysis was performed using the Bi2S3, Bi2S3/ZnO, and Bi2S3/TiO2 thin film combinations, which resulted in the degradation of Congo red increasing from 8.89% to 30.80% after a 30 min exposure to sunlight.

Solar Selective Photooxidation of Veratryl Alcohol by Suppression of Reactive Oxygen Species Through Band Modulation in the BiOI/Bi4Ti3O12 Heterojunction.

Lignin valorization through heterogeneous photocatalysis is a promising pathway for obtaining value-added products, including chemical building blocks, biofuels, etc. However, several challenges still demand attention and resolution in this field. One of the key parameters in the heterogeneous photocatalytic process is the synthesis of efficient photocatalysts that can accomplish efficient and selective reactions. Selective conversion of lignin can be achieved by using heterojunction photocatalysts which can efficiently separate charge carriers' and promote selective reactions by band structure modulation. This work details a straightforward approach for synthesizing heterojunction photocatalysts based onBi4Ti3O12and BiOI involving the hydrothermal and co-precipitation methods. Additionally, the synthesized composites were employed in the selective oxidation of veratryl alcohol, a lignin-derived model compound, to produce high-value-added veratraldehyde. The experimental results showed that the BiOI/Bi4Ti3O12heterojunction (12.5 mol %BiOI)showedsuperior activity with a veratraldehyde yield of 5.4 and 27.2 times higher than those of Bi4Ti3O12and BiOI, respectively. The mechanistic studies revealed that the improved activity and selectivity were due to the enhanced charge carriers' separation and the suppression of reactive oxygen species formation through modulation of band structure. This study allows a green approach to lignin-derived biomass valorization to obtain high-value chemicals.