Lasers Research Articles

Highly Stable Carboranyl Ligated Gold Nano-Catalysts for Regioselective Aromatic Bromination.

Achieving electronic/steric control and realizing selectivity regulation in nanocatalysis remains a formidable challenge, as the dynamic nature of metal-ligand interfaces, including dissolution (metal leaching) and structural reconstruction, poses significant obstacles. Herein, we disclose carboranyls (CBs) as unprecedented carbon-bonded functional ligands (Eads.CB-Au(111)=-2.90 eV) for gold nanoparticles (AuNPs), showcasing their exceptional stabilization capability that is attributed by strong Au-C bonds combined with B-H⋅⋅⋅Au interactions. The synthesized CB@AuNPs exhibit core(Aun)-satellite(CB2Au-) structure, showing high stability towards multiple stimuli (110 °C, pH=1-12, thiol etchants). In addition, different from conventional AuNP catalysts such as triphenylphosphine (PPh3) stabilized AuNPs, dissolution of catalytically active gold species was suppressed in CB@AuNPs under the reaction conditions. Leveraging these distinct features, CB@AuNPs realized outstanding p : o selectivities in aromatic bromination. Unbiased arenes including chlorobenzene (up to >30 : 1), bromobenzene (15 : 1) and phenyl acrylate were examined using CB@AuNPs as catalysts to afford highly-selective p-products. Both carboranyl ligands and carboranyl derived counterions are crucial for such regioselective transformation. This work has provided valuable insights for AuNPs in realizing diverse regioselective transformations.

Stability Prediction of Oxidative Active Species in Electrolytic Sulfuric Acid

Stability Prediction of Oxidative Active Species in Electrolytic Sulfuric Acid

Enhancing photocatalytic activity via formation of heterojunctions introduced through postmetalation of metal organic frameworks with silver ions

The postmetalation of silver in zinc and manganese-based metal–organic frameworks (MOFs) represents a versatile and efficient approach for enhancing the degradation of methylene blue (MB) pollutant in aqueous environment. In the present study, zinc, manganese, and their bimetallic MOFs are synthesized using the solvothermal method. Subsequently, silver ions are incorporated into the synthesized MOFs. A suite of characterization techniques is employed to analyze the resulting material. Among the three silver loaded MOFs, Ag-mixed bimetallic MOF (Ag-BM) exhibits the least band gap of 2.28 eV, possessing a greater propensity for light absorption. The particle size of Ag-BM lies in the nanometer range, and it possesses the largest surface area. X-ray diffraction depicts the successful integration of Ag into MOF structure. The synthesized samples are used for degrading MB. Ag-BM outperforms the other MOFs in decomposing MB, with a degradation percentage of 91.8% in 120 min. The degradation process follows the first-order kinetics depicting that the rate of degradation positively correlates with the dye concentration remaining in the solution. Employing a reactive species quenching experiment with scavengers, hydroxyl radicals were identified as the principal active species responsible for MB degradation by Ag-BM.

Pd Nanoparticle Supported on N‐Doped Carbon Derived from Sodium Alginate/Melamine Blends as Efficient Heterogeneous Catalyst for Heck Reactions

AbstractN‐doped porous carbon shows great potential in the field of heterogenous supports due to its high porosity, large surface area, rich active sites, and strong chelation with catalytic active metals species. Herein, we successfully prepared a novel N‐doped porous carbon derived from sodium alginate/melamine blends (SAMNC) with different mass ratio through a simple carbonization and activation process. Hierarchical porous structure of the derived N‐doped carbon has been confirmed with the SEM, TEM, and N2 adsorption characterization. After Na2PdCl4 solution impregnation and further reduction process, Pd0 nanoparticles have been uniformly immobilized on the SAMNC support to produce novel Pd@SAMNC catalyst. The optimal Pd@SAMNC‐0.6 possesses a high N content (5.13%), Pd content (5.90%), large BET specific surface area of 1884.5 m2·g−1. Positron annihilation lifetime spectroscopy (PALS) investigation of the porous carbon materials provided the sub‐nano level microporous information proofs of Pd@SAMNC‐0.6 had the capability to provide more active sites for reactions than commercial Pd supported on activated carbon (Pd@AC). Pd@SAMNC‐0.6 catalyst showed superior catalytic efficiency in Heck coupling reaction between aromatic halides and alkenes and can be recycled for 17 runs without significant decrease in catalytic efficiency.

Synthesis of MnO@Fe2O3 core-shell doped PVA/PVP polymeric nanocomposites for electronic and optoelectronic devices: Mechanical, electrical, and optical properties

Abstract The aqueous solution cast method was utilized to create biodegradable nanocomposite of polymers (PNC) films from a poly (vinyl alcohol) / poly (vinyl pyrrolidone) blend (70/30 wt%) and MnO@Fe2O3 nFs. The dislocation density, particle size, and interplanar distance were all calculated. The PNC films' surface shape changes from smooth to porous and somewhat rough because of the nanosized MnO@Fe2O3 particles' dispersion in the blend matrix, which diminishes the blended crystallites' size. The composite film's tensile strength increased from 9.45 MPa for the pure (PVA-PVP) film to 22.35 MPa due to the addition of 6 wt% MnO@ Fe2O3. The optical band gap decreases from 5.26 and 4.84 eV for pure (PVA/PVP) blend direct and indirect energy band gap to 5.18 and 4.71 eV for comparable values of 6wt% MnO@Fe2O3 nFs. Up to 6 wt% MnO@Fe2O3 concentration, PNC films' dielectric permittivity first declines, but it is substantially identical to the pure polymer blend matrix. The PNC sheet's dielectric permittivity increases nonlinearly with temperature, although its DC conductivity follows the Arrhenius law. Laser power was attenuated by (PVA- PVP)/MnO@Fe2O3 for both He-Ne and solid-state green laser beams. When the MnO@Fe2O3 concentration in the blend matrix rises to 6 wt%, the output power for lasers with 532 nm and 650 nm wavelengths drops from 5.49 to 2.4 mW and 19.8 to 9.4 mW, respectively. The findings suggest that nanocomposites exist and are widely recommended for optoelectronics, microelectronics, radiation detection, and several other uses.

An efficient, green, and magnetic recycling wastewater treatment technique enabled by ZnO/NiFe2O4/BiOBr 3D nanofibers photo-fenton process

A novel magnetic recycling ZnO/NiFe2O4/BiOBr 3D nanofibers photo-Fenton system was successfully prepared by parallel electrospinning combining with solvothermal method. ZnO/NiFe2O4 composite nanofibers was prepared via parallel electrospinning, then ZnO/NiFe2O4/BiOBr 3D nanofibers was obtained by solvothermal growth of BiOBr on electrospun ZnO/NiFe2O4 composite nanofibers. The composition, morphologies, structures and photocatalytic properties of ZnO/NiFe2O4/BiOBr 3D nanofibers were systematically tested and analyzed, and some meaningful results were obtained. The prepared ZnO/NiFe2O4/BiOBr 3D nanofibers, combined with H2O2, form a photo-Fenton system that exhibits excellent photocatalytic performance. When 0.05 mL of H2O2 is added to the photo-Fenton system, the degradation rate of organic dye Rhodamine B (RhB) reaches 99.61 % under light exposure for 10 min. Capture experiments and Electron Spin Resonance (ESR) measurements have confirmed that holes (h+) and hydroxyl radicals (·OH) are the primary active species that play a dominant role in the photocatalytic degradation of Rhodamine B (RhB). Furthermore, the ZnO/NiFe2O4/BiOBr 3D nanofibers have demonstrated exceptional photocatalytic degradation efficiency towards RhB, maintaining a degradation rate of over 95 % even after undergoing three recycling experiments. Significantly, this photo-Fenton system also has good magnetic properties, which can be separated from the treatment system under the applied magnetic field, avoiding secondary pollution of the treatment system, improving reuse rate and saving costs. This study provides valuable insights for the purposeful utilization of the photocatalytic materils.

The nature of structural defects in ZIF-8 revealed with 1H and 31P MAS NMR and X-ray absorption spectroscopy.

The metal-organic frameworks (MOFs) attract interest as potential catalysts whose catalytic properties are driven by defects. Several methods have been proposed for the defects-inducing synthesis of MOFs. However, the active species formed on the defective sites remain elusive and uncharacterized, as the spectroscopic fingerprints of these species are hidden by the regular structure signals. In this work, we have performed the synthesis of ZIF-8 MOF with defect-inducing procedures using fully deuterated 2-methylimidazolate ligands to enhance the defective sites' visibility. By combining 1H and 31P MAS NMR spectroscopy and X-ray absorption spectroscopy, we have found evidence for the presence of different structural hydroxyl Zn-OH groups in the ZIF-8 materials. It is demonstrated that the ZIF-8 defect sites are represented by Zn-OH hydroxyl groups with the signals at 0.3 and -0.7 ppm in 1H MAS NMR spectrum. These species are of basic nature and may be responsible for the catalytic activity of the ZIF-8 material.

Epoxidation at Isolated Titanium Site Modeled by Ti‐Siloxy‐Polyoxometalates Built on [α–A–XW9O34]n− and [α–B–YW9O33]9−: Comparative Study of Their Hydrolytic Stability

AbstractThis report investigates the structural differences in a series of titanium complexes constructed from silanol functionalized polyoxometalate (SiloxPOMs) derivatives, designed to create a constrained coordination site for titanium (IV) cations, namely (THA)3[PW9O34(tBuSiO)3Ti(OiPr)] and (THA)3[SbW9O33(tBuSiO)3Ti(OiPr)]. The complexes serve as structural and functional models for titanium silicates, facilitating the epoxidation of allylic alcohols and alkenes by aqueous hydrogen peroxide solutions. The different activity and selectivity observed between the two derivatives are attributed to variations in the polyoxotungstic platform used, A‐type–[XW9O34]n− versus B‐type –[YW9O33]3−. A combined experimental and theoretical investigation highlights the influence of these structural differences on water interaction and hydrolytic stability, with A‐type structures proving more susceptible to hydrolysis. In addition, the study also delves into the nuclearity of the active sites, a monomeric titanium (IV)‐hydroperoxide [Ti]–(OOH) active species evidenced by diffusion NMR spectroscopy, and the influence of the presence of water on catalytic performance in epoxidation reaction, thus shedding light on the relationship between catalyst stability, intermediates formed and reaction pathway. The study finally demonstrates the suitability of B‐type SiloxPOM derivatives as models for titanium silicates, offering insights into their stability and catalytic activity for epoxidation reactions.

The nature of structural defects in ZIF‐8 revealed with 1H and 31P MAS NMR and X‐ray absorption spectroscopy

The metal‐organic frameworks (MOFs) attract interest as potential catalysts whose catalytic properties are driven by defects. Several methods have been proposed for the defects‐inducing synthesis of MOFs. However, the active species formed on the defective sites remain elusive and uncharacterized, as the spectroscopic fingerprints of these species are hidden by the regular structure signals. In this work, we have performed the synthesis of ZIF‐8 MOF with defect‐inducing procedures using fully deuterated 2‐methylimidazolate ligands to enhance the defective sites' visibility. By combining 1H and 31P MAS NMR spectroscopy and X‐ray absorption spectroscopy, we have found evidence for the presence of different structural hydroxyl Zn–OH groups in the ZIF‐8 materials. It is demonstrated that the ZIF‐8 defect sites are represented by Zn–OH hydroxyl groups with the signals at 0.3 and –0.7 ppm in 1H MAS NMR spectrum. These species are of basic nature and may be responsible for the catalytic activity of the ZIF‐8 material.

Electron Sponge Effect by Dynamic-Regulated Electron Self-Flow toward Coupled Electrochemical Ammonia Synthesis.

A dynamic-regulated Pd-Fe-N electrocatalyst was effectively constructed with electron-donating and back-donating effects, which serves as an efficient engineering strategy to optimize the electrocatalytic activity. The designed PdFe3/FeN features a comprehensive electrocatalytic performance toward the nitrogen reduction reaction (NRR, yield rate of 29.94 μg h-1 mgcat-1 and FE of 38.43% at -0.2 V vs RHE) and oxygen evolution reaction (OER, 308 mV at 100 mA cm-2). Combining in situ ATR-FTIR, XAS, and DFT results, the role of the interstitial-N-dopant-induced electron sponge effect has been significantly elucidated in strengthening the electrocatalytic NRR process. Specifically, the introduction of a N dopant, an electron acceptor, initiates the generation of robust Lewis-acidic Fe sites, facilitating free N2 capture and bonding. Simultaneously, after NH3 adsorption, the N dopant can back-donate electrons to Fe sites, strengthening the NH3 deportation through weakening the Lewis acidity of Fe centers. Besides, the electron-deficient Fe sites contribute to the reconstruction of FeOOH, the real active species during the OER, which accelerates the four-electron reaction kinetics. This research offers a perspective on electrocatalyst design, potentially facilitating the evolution of advanced material engineering for efficient electrocatalytic synthesis and energy storage.

Construction of C3N4/Ag2S p-n semiconductor heterojunction coupled with Ag-induced SPR effect on CF cloth for improving photocatalytic activity

C3N4/Ag2S p-n semiconductor heterojunction coupled with Ag-induced SPR effect on carbon fiber cloth with large macroscopic area, recyclability and excellent photocatalytic performance was prepared by thermal condensation-chemical precipitation. CF/C3N4/Ag/Ag2S cloth showed strong Vis-NIR light absorption and outstanding separation efficiency of photo-generated electron and hole pairs. CF/C3N4/Ag/Ag2S cloth displayed a markedly enhanced catalytic activity (94 % of TC, 85 % of Cr(VI)) compared with CF/C3N4 cloth (52 % of TC, 50 % of Cr(VI)) or CF/Ag/Ag2S cloth (34 % of TC, 19 % of Cr(VI)), attributing to the establishment of p-n junction along with Ag SPR effect. Moreover, degradation pathways for TC were proposed utilizing HPLC-MS and Fukui index analysis, and photocatalytic mechanism was confirmed by active species experiments and DFT computations. This facile strategy provides novel approach to the synthesis of material with large macroscopic areas, recyclability, and excellent photocatalytic property for degrading contaminants from wastewater.

Synergistic enhancement of plasmon induced photocatalytic and photoelectrochemical performance on ZnWO4/Ag2O@Ag hybrid-heterostructures

A novel hybrid photocatalyst, ZnWO4/Ag2O@Ag heterostructure was synthesized using a simple one-pot microwave treatment with varying concentrations of silver. Physico-chemical characterization was performed to elucidate the synthesized nanohybrids' properties. The photocatalytic activity of both pristine and heterostructure samples was evaluated through the degradation of cationic MB dye. Among the varied Ag concentrations, the 9 % Ag-doped ZnWO4/Ag2O heterostructure exhibited superior degradation performance, with a degradation rate of 93 % achieved within 45 min, surpassing both other Ag concentrations (89 % (90 min) for 1 % Ag, 87 % (80 min) for 3 % Ag, 90 % (80 min) for 5 % Ag and 91 % (45 min) for 7 % Ag) and pristine ZnWO4 (91 % (90 min)) samples. This catalytic enhancement can be attributed to the formation of heterostructures, plasmon-induced absorption enhancement within specific wavelength ranges, and reduced charge recombination rates. UV–visible studies revealed Ag nanoparticles of various sizes in the heterostructures, supported by surface plasmon resonance (SPR) peaks at 480 and 550 nm, respectively. Trapping experiments indicated that •OH and •O2− were the active species in MB reduction for pure and heterostructure samples. Furthermore, the hybrid heterostructure samples exhibited high stability and reusability in photocatalytic degradation. These findings suggest that the ZnWO4/Ag2O heterostructure photocatalysts are promising candidates for environmental remediation applications.

Metabolic rate does not scale with body size or activity in some tick species.

Respiration in ticks is highly efficient and exceptionally low. Ticks can survive years between bloodmeals by having low activity and respiration to conserve energetic resources. Our objective was to compare metabolic (VCO2) and activity rates across 6 tick species. We predicted that VCO2 would be different among species and scale linearly with activity and body mass. Activity and CO2 production were measured for 32h in 6 tick species: Dermacentor andersoni, D. variabilis, Haemaphysalis longicornis, Rhipicephalus appendiculatus, R. microplus, and R. sanguineus. Individual ticks were measured for 30min three times to ensure breathing occurred. Absolute and mass-specific VCO2, total activity, body mass, and ventilation patterns were compared among species. As expected, ticks did not always breathe during the 30-minute measurements, especially R. sanguineus. Ventilation patterns differed among species with R. microplus having primarily cyclic patterns and R. appendiculatus having discontinuous gas exchange. VCO2 did not scale with body mass in most species. Haemaphysalis longicornis and R. sanguineus had the lowest VCO2; however, H. longicornis was the second most active species. Life history, including questing behavior and range expansion, could be contributing to differences between species. For instance, H. longicornis had exceptionally low metabolic rates despite above average activity levels, suggesting an energetic advantage which may underlie recently documented range expansions in North America. Our results demonstrate how ticks utilize energetic resources to maximize longevity. Future research describing questing behavior and distribution modeling may help explain differences in metabolic rates and activity and impacts on life history traits.

Piezo‐catalysis Mechanism Elucidation by Tracking Oxygen Reduction to Hydrogen Peroxide with In situ EPR Spectroscopy

AbstractFor piezoelectric catalysis, the catalytic mechanism is a topic of great controversy, with debates centered around whether it belongs to the energy band theory or the screening charge effect which are similar to mechanisms of photocatalysis and electrochemical catalysis, respectively. Due to the formation of different intermediate active‐species during two‐electron oxygen reduction reaction (ORR) via electro‐ and photo‐catalysis, the key to solving this problem is precisely monitoring the active species involved in ORR during electro‐, photo‐, and piezo‐catalysis under identical condition. Here, a semiconductor material, BiOBr with abundant oxygen vacancies (BOB‐OV) was found remarkable catalytic activity in H2O2 production by all three catalytic methods. By employing in situ electron paramagnetic resonance (EPR) spectroscopy, the H2O2 evolution pathway through piezo‐catalysis over BOB‐OV was monitored, which showed a similar reaction pathway to that observed in photo‐catalytic process. This finding represents solid evidence supporting the notion that piezo‐catalytic mechanism of ORR is more inclined towards photo‐catalysis rather than electro‐catalysis. Significantly, this exploratory conclusion provides insight to deepen our understanding of piezo‐catalysis.

Piezo-catalysis Mechanism Elucidation by Tracking Oxygen Reduction to Hydrogen Peroxide with In-situ EPR Spectroscopy.

For piezoelectric catalysis, the catalytic mechanism is a topic of great controversy, with debates centered around whether it belongs to the energy band theory of photocatalysis or the screening charge effect of electrochemical catalysis. Due to the formation of different intermediate active-species during two-electron oxygen reduction reaction (ORR) via electro- and photo-catalysis, the key to solving this problem is precisely monitoring the active species involved in ORR during electro-, photo-, and piezo-catalysis under identical condition. Here, a semiconductor material, BiOBr with abundant oxygen vacancies (BOB-OV) was found remarkable catalytic activity in H2O2 production by all three catalytic methods. By employing in-situ electron paramagnetic resonance (EPR) spectroscopy, the H2O2 evolution pathway through piezo-catalysis over BOB-OV was monitored, which showed a similar reaction pathway to that observed in photo-catalytic process. This finding represents solid evidence supporting the notion that piezo-catalytic mechanism of ORR is more inclined towards photo-catalysis rather than electro-catalysis. Significantly, this exploratory conclusion provides insight to deepen our understanding of piezo-catalysis.

Enhanced the removal of norfloxacin by oxalated zero-valent iron with rich surface Fe(II) sites activating the chlorite

Oxalic acid-modified ball-milled zero-valent iron (OA-ZVIbm) was employed to activate sodium chlorite (ClO2-) for the removal of norfloxacin (NOR). The complete removal of 20 mg/L NOR was achieved within 60 min by the OA-ZVIbm/ClO2- process. Compared with the ZVIbm/ClO2- process which was the ball-milled zero-valent iron (ZVIbm) activate sodium chlorite, the reaction activity of the OA-ZVIbm/ClO2- process was increased by 102.6 times. Through scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), electrochemical testing, and density functional theory (DFT) calculations, which has been confirmed that the introduction of oxalic acid can significantly increase the surface Fe(II) content of OA-ZVIbm, and accelerate the electron transfer rate of iron nuclei, thereby improve the efficiency of ClO2- activation for the removal of NOR. The role of various active species in NOR removal, which were •O2-, 1O2, Fe(IV), ClO2, and •OH, was elucidated through free radical quenching experiments, electron paramagnetic resonance (EPR) spectroscopy, and quantitative detection of active species. These active species all participated in the reaction, while •O2- played a dominant role in the reaction because it could transform into other active species, such as (•OH, 1O2). Inorganic anions and natural organic matter have no significant effect on the removal of NOR in the OA-ZVIbm/ClO2- process. The protonation of oxalic acid ensured its good pH applicability range (pH = 2–11), thus exhibiting excellent performance in NOR removal in real water bodies. This further demonstrates that OA-ZVIbm prepared by oxalic acid ball milling modification is an efficient ClO2- activator, offering promising prospects for antibiotic removal technology.

A novel persulfate activation strategy by double Z-scheme Bi2O3/CuBi2O4/BiOBr heterojunction: Non-radical dominated pathway for levofloxacin degradation

Persulfate advanced oxidation technology (PS-AOPs) is known as a novel wastewater treatment method. Considering the poor self-stability of Bi2O3/CuBi2O4, we synthesized Bi2O3/CuBi2O4/BiOBr ternary composite material and established the non-radical pathway-dominated peroxymonosulfate (PMS) activation system. The study indicated that BiOBr promoted electron migration on the material surface. Bi2O3/CuBi2O4/BiOBr/Vis/PMS system exhibited excellent catalytic performance (86.83 % within 100 min), significantly higher than Bi2O3/CuBi2O4 (63.19 %) and BiOBr (60.35 %). Furthermore, it has strong catalytic activity and adaptability to various environmental conditions. By quenching experiments and EPR analysis, O2−∙ and 1O2 were the main active species. Finally, possible degradation pathways and intermediates were predicted through liquid mass spectrometer (LC-MS), and toxicity analysis was conducted on levofloxacin (Lev) and intermediates. The degradation mechanism may be attributed to the construction of double Z-scheme heterojunction, photogenerated electron transfer and ROS generation through the redox cycle of Cu2+/Cu+ and Bi5+/Bi3+.

Visible-light-driven selective cleavage of lignin C-C bonds on the TiO2@g-C3N4 heterostructured photocatalyst.

The selective cleavage of lignin C-C bonds is a highly sought-after process with the goal of obtaining low-molecular-weight aromatic chemicals from renewable resources. However, it remains a challenging task to achieve under mild conditions. Photocatalysis is a potentially promising approach to address this issue, but the development of efficient photocatalysts is still in progress. In this study, we introduce the heterostructured TiO2@g-C3N4 photocatalyst for the development of a visible light photocatalytic procedure for the selective cleavage of lignin C-C bonds under mild conditions. The photocatalyst displays favourable visible light absorption, efficient charge separation efficiency, and promising reusability. A typical β-O-4 dimer model, 2-phenoxy-1-phenylethanol, was effectively (96.0% conversion) and selectively (95.0 selectivity) cleaved under visible light at ambient conditions. This photocatalytic procedure was also effective when subjected to solar irradiation or other lignin dimer models with β-O-4 or β-1 linkages. This reaction occurred through a Cβ-centred radical intermediate and a six-membered transition state with photogenerated holes as the primary active species. The Cα-OH oxidative dehydrogenation of the substrate could also take place but was a relatively minor route. This study provides a new photocatalytic procedure for visible-light-driven lignin valorisation and sheds light on the design of high-performance nanocomposite photocatalysts for C-C bond cleavage.&#xD.

Efficient selective cleavage of C−C bonds in lignin under visible light enabled by the Fe-doped mesoporous graphitic carbon nitride photocatalyst

To obtain high-valued aromatic products, it is paramount to cleave the Cα−Cβ bonds in lignin under mild conditions selectively. Nevertheless, this task remains daunting due to the formidable dissociation energies and steric hindrance associated with these bonds. Herein, a facile, efficient and cost-effective strategy for selectively breaking the Cα−Cβ bond in lignin with visible-light irradiation and room temperature is proposed, facilitated by the utilization of the ferric-doped mesoporous graphitic carbon nitride (Fe/mpg-CN) photocatalyst. Collective contributed by the reduced band gap and photoluminescence, combined with intensified visible-light absorption and enhanced photocurrent, the effectiveness in photocatalytic activity of Fe/mpg-CN is offered. Specifically, a high conversion rate (98 %) of the lignin model compound (2-phenoxy-1-phenylethanol), coupled with an excellent selectivity of 98 % in cleaving the Cα−Cβ bonds is achieved by Fe/mpg-CN. Photogenerated holes are indicated as the main active species through comprehensive mechanistic investigations. Additionally, the successful photocatalytic depolymerization of the complex dimer model compound (conversion rate ∼ 96 %) and pine kraft lignin further corroborate the satisfying photocatalytic activity and selectivity of Fe/mpg-CN. This study introduces a promising and viable strategy for the selective breaking of lignin through photocatalysis, offering significant implications for the sustainable production of valuable aromatic compounds.

Enhanced photocatalytic performance of ternary g-C3N4/UiO-66/Ag3VO4 composite for methylene blue degradation under visible light irradiation

Anovel Ag3VO4/UiO-66/g-C3N4-based photocatalystwassynthesized using the solvothermal approach and characterized using XRD, SEM, FTIR, PL, and UV–Vis DRS. The photodegradation capacityof each componentwas tested using aqueous solutions of methylene blue (MB) and real sample solutions. It was found that the ternary composites (g-C3N4/UiO-66/Ag3VO4, 1 wt%, 5 wt%, 10 wt%, and 15 wt% g-C3N4) demonstrated higher degradation efficiency than the single and binary constituentsowing to beneficial interactions in the composite, which favor successful interfacial charge transfer and improve photogeneratede--h+pair separations. The influence of various experimental factors such as pH, initial dye amount, photocatalyst dose, and scavengers on MB degradation was examined. At optimal conditions of pH 6, catalyst load of 60 mg, and initialdye content of 10 ppm, the percent photodegradation of MB under irradiation with visible light (indoorsystem) was 99.35 %, while in the outdoor system,it was 99.5 % in 240 min. The selected photocatalyst was also applied for the degradation of real sewage sample solution, which was found to be 80.2 % under indoor and 89 % under outdoor experimental undertakings. After five cycles, the potential of the photocatalystremained substantial, indicating remarkable reusability. The scavenging experiment suggested that the principal active species were found to be superoxide (O2•) and hydroxide radicals (•OH). Thus, the composite g-C3N4/UiO-66/Ag3VO4 could be a promising option for industrial effluent removalapplications, particularly in the purification of organic dye-containing wastewater.