Photocatalytic Degradation Of Pollutants Research Articles

Photocatalytic Degradation of Pollutants Using Advanced Ceramics: Materials, Mechanism, Synthesis, and Applications

Photocatalytic Degradation of Pollutants Using Advanced Ceramics: Materials, Mechanism, Synthesis, and Applications

Recent Developments in Porphyrin-Based Metal–Organic Framework Materials for Water Remediation under Visible-Light Irradiation

Access to clean drinking water is a basic requirement, and eliminating pollutants from wastewater is important for saving water ecosystems. The porous structure and surface characteristics of metal–organic frameworks (MOFs) can function as a perfect scaffold for removing toxic compounds from wastewater. Porphyrins are promising building blocks for constructing MOFs. Porphyrin-based metal–organic frameworks (P-MOFs) have been fabricated using porphyrin ligands, metal clusters, or ions. These materials can harvest light from a wide region of the solar spectrum, and their framework morphology and physicochemical properties can be controlled by changing their peripheral subunits or metal ions. These porous crystalline materials have generated interest because of their distinctive characteristics, including large permanent porosity, interesting surface morphology, broad conformational diversity, high photostability, and semiconducting nature. This article discusses the recent progress and usefulness of P-MOFs. The fabrication procedures of P-MOFs are discussed, followed by the adsorptive and photocatalytic removal of contaminants from wastewater. The relationships between the geometries of P-MOFs and their light-harvesting and charge-transfer mechanisms for the photocatalytic degradation of pollutants are highlighted. Finally, some future perspectives and obstacles in the photodegradation usage of P-MOFs are discussed, along with feasible research directions to standardize efficient photocatalysts for improved photodegradation for water treatment.

Constructing a type-II heterojunction of AgI/CO32−-Bi2O2CO3 for enhanced photocatalytic degradation of organic pollutants

The construction of heterojunctions is a well-established approach for enhancing the photocatalytic efficiency of semiconductor materials. To improve the photocatalytic activity of CO32−-Bi2O2CO3, AgI/CO32−-Bi2O2CO3 type-II heterojunction photocatalysts were synthesized using an electrostatic self-assembly method with varying composite ratios. The performance of AgI/CO32−-Bi2O2CO3 catalyst was investigated by photocatalytic degradation of 2-Hydroxy-1, 4-naphthoquinone and levofloxacin under a 300 W xenon lamp (λ ≥ 420 nm). The results demonstrated that the composite photocatalyst (0.5ACBOC), prepared by incorporating 0.5 mL of AgNO3 and KI, exhibited exceptional photocurrent responsiveness and efficient charge carrier separation. 0.5ACBOC displayed the highest degradation efficiency towards 2-Hydroxy-1,4-naphthoquinone (67.5%) and levofloxacin (78.0%). Free radical capture experiments and electron paramagnetic resonance (EPR) analysis revealed ·O2− as a crucial reactive species in the photodegradation process. Moreover, the photocatalytic degradation of 2-Hydroxy-1,4-naphthoquinone exhibited consistent removal efficiency even after undergoing four cycles, thereby demonstrating the excellent cycle stability of the composite catalyst. These findings highlight that AgI/CO32−-Bi2O2CO3 can be easily synthesized and holds great potential as a photocatalyst for efficient degradation of organic pollutants.

S-Schematic CuWO4/ZnO nanocomposite boosted photocatalytic degradation of organic dye pollutants

S-schematic CuWO4/ZnO nanocomposite photocatalyst was synthesized by an impregnation method. Synthesized CuWO4 and ZnO nanoparticles, and CuWO4/ZnO nanocomposites were thoroughly characterized. X-ray diffraction (XRD) analysis of the CuWO4/ZnO nanocomposite confirmed the respective triclinic and hexagonal wurtzite structures of CuWO4 and ZnO crystals. Raman and Fourier transform infrared (FTIR) spectra and X-ray photoelectron spectroscopy (XPS) revealed bond formations in CuWO4 and ZnO, and confirmed the synthesis of the CuWO4/ZnO nanocomposite. Scanning electron microscopy (SEM) and transmission electron microscopy (TEM) revealed CuWO4 nanoparticles adhered to ZnO aggregates. Energy dispersive X-ray spectrometry (EDS) confirmed the distribution of CuWO4 on the ZnO aggregates. UV–Vis diffuse reflectance spectroscopy (DRS) showed optical bandgap energies of 2.36 eV for CuWO4 and 3.18 eV for ZnO nanoparticles. The photocatalytic performance of the CuWO4/ZnO nanocomposite was investigated through the degradation of the cationic dyes methylene blue (MB) and Rhodamine B (RhB) and the anionic dye methyl orange (MO). A 5.0%CuWO4/ZnO nanocomposite degraded 100% of MB within 120 min, 91.02% of RhB within 300 min, and 89.13% of MO within 300 min. The pseudo-first order kinetic rate constant fit well for the degradation of all the dyes on the CuWO4/ZnO nanocomposite. The CuWO4/ZnO nanocomposite could better degrade the cationic dyes than the anionic dye in an aqueous solution. The hole (h+), the hydroxyl radical (•OH), and the superoxide ion (•O2−) were the active species responsible for degrading MB, RhB and MO dyes. The proposed CuWO4/ZnO nanocomposite could be applied for environment friendly wastewater treatment.

Enhanced Photocatalytic and Electrochemical Performance of MOF-Derived NiO-ZnO Oxide Composites for Wastewater Treatment and Sustainable Energy Storage

Solar energy is a crucial and sustainable resource, necessitating material optimization for efficient use in solar-driven applications, particularly photocatalysis. Mixed-metallic nanocomposites, notably those derived from metal-organic frameworks (MOFs), have emerged as promising functional materials for environmental remediation and electrochemical energy storage. MOFs provide unique platforms for synthesizing diverse nanostructures, incorporating metals, oxides, sulfides, and nitrides within a porous carbon matrix. These resulting nanocomposites exhibit high crystallinity, retained morphologies, and tunable textural features. This study focuses on synthesizing a MOF-derived Ni/Zn nanocomposite (i.e., MD-Ni/Zn) from a bimetallic MOF to exploit its potential in photocatalytic pollutant degradation and electrochemical energy storage. Under UV irradiation, the MD-Ni/Zn nanocomposite efficiently degrades 98% of mixed (RhB+CV) dye within 60 minutes. This remarkable photocatalytic performance is attributed to the occurrence of mixed phases in the MD-Ni/Zn nanocomposite, minimizing the recombination efficiency of photoinduced e-/h+ through the p-n heterojunction mechanism. Electrochemical analysis reveals outstanding capacitance in the MD-Ni/Zn nanocomposite, reaching 1002 F/g at 5 A/g, emphasizing its suitability for enhanced electrochemical energy storage.

Sunlight driven photocatalytic degradation of organic pollutants by solvothermally synthesized rGO-BiVO4 nanohybrids

This study reports photocatalytic degradation of organic dyes by rGO-BiVO4 nanohybrids. rGO- BiVO4 nanohybrids were solvothermally prepared with different rGO loading (1.5, 3 and 6 %) and their structural, optical and photocatalytic properties were investigated. Effect of rGO loading on photocatalytic dye degradation was studied and the factors responsible were analyzed. Structural analysis was done using XRD and Raman analyses which clearly showed monoclinic phase of the BiVO4. FESEM images showed sub-micron spheres of BiVO4 along with sheet-like structures corresponding to rGO. A slight change in the band gap was observed from 2.2 eV for BiVO4 to around 2 eV for the rGO-BiVO4 nanohybrids. Band to band transitions as well as the transitions from the defect bands were observed from the PL spectra. Photocatalytic degradation studies of organic pollutant MB under natural sunlight showed 3 % rGO-BiVO4 to be the best photocatalyst which degraded 88.4 % of MB in 80 min with rate constant of 0.0244 min−1. It was observed that for obtaining a maximum catalytic efficiency an optimum loading of rGO proved to be best. In either case of higher or lower loading of rGO showed a lower degradation performance. Amongst the samples synthesized 3 % rGO loading was found to be the optimum rGO loading to have the lowest band gap (2 eV) as well as the reduced recombination that has resulted in highest photocatalytic efficiency under solar irradiation.

Crafting defective ZnO nanoparticles: A green synthesis for enhanced photocatalytic degradation of organic pollutants

Surface defect engineering is a promising strategy for enhancing the number of surface-active sites to facilitate efficient redox reactions that occur on the surface of a photocatalyst. A green approach was employed to prepare urea- and choline-chloride-based deep eutectic solvent (DES) for the synthesis of ZnO/Zn(OH)2 supported by a DES complex (Zn precursor). Surface defects on ZnO nanoparticles (NPs) were tailored by decomposing the Zn precursor in air. In addition, calcination improved the crystallinity and surface-active sites of the defective ZnO by creating surface oxygen vacancies (Vo). The appearance of an Electron paramagnetic resonance peak at a g value of 1.96 confirms the formation of single-charged Vo defects on the surface of ZnO. The photocatalyst prepared at a reaction bath temperature of 75 °C (Vo-ZnO-75) showed the highest photocatalytic activity. The observed green emission in the photoluminescence spectrum and X-ray photoelectron spectroscopy analysis suggests the formation of defects on the ZnO surface. Consequently, Vo-ZnO-75 enhanced surface donor density (14.4×1020 cm−2) and lower charge transfer resistance (88.89 × 103 Ω). The optimized photocatalyst of Vo-ZnO-75 has 94% removal efficiency for rhodamine B degradation within 60 min. This study sheds new light on the development of an efficient and eco-friendly approach for preparing defective ZnO NPs for photocatalytic applications.

Fabrication and characterization of new Fe3O4@SiO2@TiO2-CPTS-HBAP (FST-CH) nanoparticles for photocatalytic degradation and adsorption removal of rhodamine B dye in the aquatic environment

In this study, Fe3O4@SiO2@TiO2-CPTS-HBAP (FST-CH) nanoparticle was prepared for the simultaneous adsorption and photocatalytic degradation of aromatic chemical pollutants (Rhodamine B dye) in aqueous solution. FST-CH nanoparticle was characterized using scanning electron microscopy (SEM), Fourier-transform infrared spectroscopy (FTIR), Energy Dispersive X-Ray (EDX) Fluorescence Spectrometer and X-Ray Diffraction (XRD) spectroscopy. The photocatalytic activity of rhodamine B dye (RhB) was evaluated with a Kerman UV 8/18 vertical roller photoreactor. About 56% of RhB in aqueous medium was adsorbed by FST-CH nanoparticles with only 45 min of stirring in the dark, and about 77.01% was degraded or converted to other structures under the photoreactor for 120 min. The photocatalytic degradation of RhB (apparent rate constant: 0.0026 mg dm-3 min-1) occurred by a pseudo-second order reaction. In addition, the recovery of the prepared magnetic FST-CH nanoparticle by an external magnetic field, exhibiting good magnetic response and reusability, shows that the obtained magnetic FST-CH nanoparticle is stable and maintains high degradation ratio and catalyst recovery even after four cycles. Thus, the prepared FST-CH nanoparticle can be highly recommended for its use in potential applications of water decontamination.

Fabrication of Ag-decorated La0.9Ag0.1FeO3 for efficient photocatalytic degradation of tetracycline under visible light with the assistance of water oxidation

The photocatalytic conversion of molecular O2 into reactive oxygen species, such as superoxide radicals (·O-2), has become the focus in the oxidative removal of organic pollutants. Nevertheless, the inefficient light absorption, limited adsorption of O2, and the fast recombination rate of photo-induced electron-hole pairs considerably impede the conversion efficiency of the photocatalysts. Herein, we report the synthesis of Ag@LAFO photocatalyst, which contains Ag nanoparticles (NPs)-decorated LAFO (Ag-substituted LaFeO3), to enhance the photodegradation efficiency of tetracycline (TC) with the assistance of water oxidation. Structural and spectroscopic analyses confirmed the successful decoration of Ag NPs on LAFO, which was prepared by substituting 10% La with Ag. The efficiency of TC photocatalytic degradation rate of Ag@LAFO is 76.25%, which is 6.1-fold higher than that of pure LFO (12.41%). The trapping experiment of active radicals verified that ·O-2 was crucial in the decomposition of TC molecules and was continuously supplied by the reduction of O2 molecules supported by photocatalytic water oxidation. Moreover, the Ag NPs in Ag@LAFO were found to be crucial for boosting the capture of photo-induced electrons and the activation of adsorbed O2. This study offers a new perspective on the conversion of O2 to ·O-2 with the assistance of photocatalytic water oxidation for photocatalytic degradation of organic pollutants.

Photocatalytic degradation of persistent antibiotic pollutants by MOF-derived bird-nest ferric molybdate

A photocatalyst (PC) with an optimized morphology exhibits better pollutant photodegradation because of the augmentation of the surface area available for redox reactions and light harvesting. Here, we synthesized a Fe2(MoO4)3 (FMO) PC from a coordinated Fe metal-organic framework (MOF) precursor. During this process, FMOMOF was pyrolyzed to rearrange the organic structure of the Fe-MOF precursor. This synthesis strategy resulted in a unique PC made of stacked nanosheets (NSs) organized in a bird-nest structure. Compared to smooth FMOFC spheres synthesized from uncoordinated Fe ions, FMOMOF exhibited a 3.6-time larger surface. In addition, FMOMOF NSs were accompanied by smaller nanoparticle and quantum dot satellites, which expedited charge separation. FMOMOF was evaluated for the photodegradation of the polluting antibiotics tetracycline hydrochloride (TCH) and oxytetracycline hydrochloride (OTCH). The PC readily photodegraded above 90 % of both antibiotics and completely mineralized a large fraction. Illuminated FMOMOF oxidized TCH and OTCH 1.6 to 3.0 times faster than FMOFC and was also reusable. A larger surface exposing more redox sites and a better charge separation efficiency were responsible for the improved photooxidation performance of FMOMOF. Thus, these results describe how a MOF precursor can be employed to develop a promising FMO PC capable of removing recalcitrant antibiotics.

Construction of a direct Z-scheme Cs3Bi2Cl9/g-C3N4 heterojunction composite for efficient photocatalytic degradation of various pollutants in water: Performance, kinetics and degradation mechanism

The use of emerging composite materials has been booming to remove environmental pollutants. The aim of this research is to develop a new composite based on Cs3Bi2Cl9 perovskite and graphitic carbon nitride (g-C3N4) to investigate the photocatalytic performance under visible light irradiation. To achieve this, we produce the Cs3Bi2Cl9/g-C3N4 heterojunctions through a simple self-assembly synthesis. The as-synthesized composites are characterized using XRD, FTIR, FESEM, TEM, BET and EDX techniques. The photocatalytic performance of Cs3Bi2Cl9/g-C3N4 is examined in the degradation of various water contaminants, including 4-nitrophenol (4-NP), tetracycline antibiotic (TC), methylene blue (MB) and methyl orange (MO). The experimental results indicate the superior photocatalytic performance of the composites in the degradation of pollutants compared to pure Cs3Bi2Cl9 and g-C3N4. The 10% Cs3Bi2Cl9/g-C3N4 composite achieves the optimal degradation efficiency of 100, 92, 98.7, and 85.1% of 4-NP, TC, MB, and MO, respectively. This superior photocatalytic activity attributes to improved optical and electrochemical properties, including enhanced absorption ability, narrowing band gap, promoted separation efficiency of photogenerated carriers, and a high redox potential, which is confirmed by UV–vis DRS, PL, EIS, and CV analyses. The 10% Cs3Bi2Cl9/g-C3N4 composite also demonstrates high photocatalytic stability after four consecutive cycles. Radical trapping tests show that superoxide radicals (•O2−), holes (h+), and hydroxyl radicals (•OH) contribute to the photocatalytic process. Based on the obtained data, a direct Z-scheme heterojunction mechanism is proposed. Overall, this research offers a new stable photocatalyst with excellent prospect for photocatalytic applications.

Construction of A-FeOx/LaFeO3 hybrid microreactors for efficient photocatalytic degradation of organic pollutants

Low-dimensional hybrid nanocrystals are newly emerging active photocatalysts for separating electron-hole pairs, but the instability and low quantum efficiency caused by particle aggregation and hybrid structure relaxation remain great challenges. To this end, herein we constructed amorphous FeOx (A-FeOx) and crystalline LaFeO3 hybrids by a sol-gel method. The amorphous-crystalline hybrids, A-FeOx/LaFeO3, not only improve the surface area and alter the band position, but also form numerous channels that are conducive to the transport of electrons and separation of electron–hole pairs, acting as microreactors. Photocatalytic tests show that the A-FeOx/LaFeO3 is highly active for the degradation of various organic pollutants, with reaction rate constant of 1.19 × 10–2 min–1 for ciprofloxacin degradation, for example, which is 1.82 and 1.87 times higher than that of LaFeO3 and Fe2O3/LaFeO3, respectively, owing to the formation of microreactors between A-FeOx and LaFeO3. Cycling tests show that the material has good stability in the reaction, and trapping experiments demonstrate that the photo-induced holes are the main reactive species of the reaction. This work provides a novel and feasible insight into the design of high performance low-dimensional hybrid nanocatalysts for photocatalysis.

Lignin-modified graphitic carbon nitride nanotubes for photocatalytic H2O2 production and degradation of brilliant black BN

As a renewable aromatic compound with enormous production potential, lignin has various potential high-value utilization pathways, but the success achieved in the field of photocatalysis is limited. Herein, this work prepares a new type of photocatalyst by modifying Graphitic Carbon Nitride Nanotubes (CNT) with self-assembled lignin nanospheres for the photocatalytic production of H2O2 and the degradation of azo dyes. Under light conditions, lignin enhances the production of H2O2 through oxygen reduction and collaborates with carbon nitride tubes to generate O2− and 1O2. Furthermore, carbon nitride tubes form electron-rich regions with lignin, promoting the transfer of electrons from adsorbed aromatic pollutants to this region, thereby facilitating their degradation. The experimental results indicate that the addition of 5 % lignin significantly enhances the photocatalytic degradation efficiency of azo dyes, with a degradation rate 1.87 times higher than that of the original carbon nitride tubes. Furthermore, CNL also have excellent degradation ability to pollutants in actual wastewater. This study provides new insights and prospects for the high-value utilization of lignin, enabling it to be used as a photocatalytic co-catalyst to participate in the photocatalytic degradation of environmental pollutants.

The inhibitory effect of natural organic matters and ions on 17ɑ-ethinylestradiol removal over new TiO2(B)/Bi5O7I and mesoporous carbon/TiO2(B)/BiOI composites: The role of mesoporous carbon

The natural organic matters (NOMs) and ions prevalent in water matrixes always inhibits photocatalytic degradation of pollutants by TiO2. Herein, we prepared TiO2(B)/Bi5O7I and mesoporous carbon/TiO2(B)/BiOI composites to investigate the inhibitory effect of NOMs and ions on photocatalytic degradation of 17ɑ-ethinylestradiol (EE2). The results show that Bi5O7I or BiOI is tightly anchored onto the large surface of TiO2(B) nanobelt to form heterojunction, and metallic Bi forms on the surface of TiO2(B) in MC/TiO2(B)/BiOI composite. This intimate contact is beneficial for the separation of hole-electron pairs and stability. More importantly, the introduction of mesoporous carbon (MC) not only improve the EE2 removal but also eliminate obvious inhibitory effect of NOMs and inorganic ions. The main cause is that MC component in MC/TiO2(B)/BiOI composite can preferentially adsorb EE2 molecules from water via π-π and hydrophobic interaction forces between EE2 and MC. Quenching experiments and electron paramagnetic resonance confirm that •O2- and h+ are main reactive species for EE2 degradation over both TiO2(B)/Bi5O7I and MC/TiO2(B)/BiOI composites. Besides, the degradation mechanism was investigated, and degradation pathways are proposed based on intermediates identification. The MCF-7 cell test shows that the estrogenic activity of the treated solution can be rapidly eliminated. More importantly, MC/TiO2(B)/BiOI has excellent anti-interference capacity for the EE2 removal in real complex water matrixes.

Superparamagnetic Dy modified ZnFe2O4 magnetic nanophotocatalysts for the photocatalytic degradation of crystal violet pollutant

Superparamagnetic Dy modified ZnFe2O4 magnetic nanophotocatalysts for the photocatalytic degradation of crystal violet pollutant

Effective Interfacing of Surface Homojunctions on Chemically Identical g-C3N4 for Efficient Visible-Light Photocatalysis without Sacrificial Agents.

Developing efficient homojunctions on g-C3N4 promises metal-free photocatalysis to realize truly sustainable artificial photosynthesis. However, current designs are limited by hindered charge separation due to inevitable grain boundaries and random formation of ineffective homojunctions embedded within the photocatalyst. Here, efficient photocatalysis is driven by introducing effective surface homojunctions on chemically and structurally identical g-C3N4 through leveraging its size-dependent electronic properties. Using a top-down approach, the surface layer of bulk g-C3N4 is partially exfoliated to create sheet-like g-C3N4 nanostructures on the bulk material. This hierarchical design establishes a subtle band energy offset between the macroscopic and nanoscopic g-C3N4, generating homojunctions while maintaining the chemical and structural integrities of the original g-C3N4. The optimized g-C3N4 homojunction demonstrates superior photocatalytic degradation of antibiotic pollutants at >96% efficiency in 2h, even in different real water samples. It achieves reaction kinetics (≈0.041min-1) up to fourfold better than standalone materials and their physical mixture. Mechanistic studies highlight the importance of the unique design in boosting photocatalysis by effectively promoting interfacial photocarrier manipulation and utilization directly at the point-of-catalysis, without needing co-catalysts or sacrificial agents. This work presents enormous opportunities for developing advanced and green photocatalytic platforms for sustainable light-driven environmental, energy, and chemical applications.

A review on ZnO and its modifications for photocatalytic degradation of prominent textile effluents: Synthesis, mechanisms, and future directions

Effective and eco-friendly approaches are essential for dealing with organic pollutants in industrial waste. Textile dyes are toxic and carcinogenic, and releasing them into the environment leads to water pollution, posing significant health risks to all living beings and endangering aquatic life. The use of semiconducting metal oxides for photocatalytic pollutant degradation has emerged as an advanced wastewater treatment strategy. The multifunctional nature of ZnO, stemming from its affordability, environmentally friendly characteristics, structure-dependent properties, and ability to fully mineralize pollutants, positions it as a superior photocatalyst compared to other materials. However, its primary drawback is poor performance in visible light. This review delves into various synthesis techniques and their effects on morphology, structure, and band gap, and its subsequent influence on the photocatalytic performance. The review highlights the effect of doping ZnO with various alkaline earth metals, transition metals, noble metals, rare earth metals, and non-metals, along with studies reported on ZnO-metal oxide nanocomposites for photocatalytic dye degradation, by providing insights into the photodegradation mechanism involved. Furthermore, this review extensively investigates the strategies to improve ZnO's efficiency in degrading textile dyes, namely cationic and anionic dyes, under visible light conditions. For thorough understanding, the influence of various operational parameters such as catalyst loading, irradiation source, dye concentration, reaction time, and reaction kinetics on photocatalytic efficiency have been investigated in detail. The review also addresses existing challenges and potential future directions, providing some insights for possible development in this field.

Preparation and characterization of a chitosan/TiO2 nanocomposite hydrogel intended for the photocatalytic degradation of pollutants

Preparation and characterization of a chitosan/TiO2 nanocomposite hydrogel intended for the photocatalytic degradation of pollutants

Self-standing CdS/TiO2 Janus nanofiberous membrane: COD removal, antibacterial activity and photocatalytic degradation of organic pollutants

The self-standing TiO2 nanofiber-based heterojunction with excellent visible-light-driven photocatalytic activity, antimicrobial activity, and reusability holds great importance in water and airborne pollutant management. Herein, a series of splendid flexible CdS/TiO2 (CdS/TZ) nanofibrous membranes (NFMs) were fabricated by facile post-electrospinning treatment. The self-standing TiO2 NFM was first prepared via the electrospinning technique followed by controlled calcination, and then the CdS nanoparticles (NPs) were grown by the successive ionic layer adsorption and reaction (SILAR) method. The careful deposition of CdS NPs preserved the self-standing properties of the TiO2 membrane. The amount of CdS NPs in the CdS/TiO2 membrane was tailored by varying the SILAR cycles. The CdS/TiO2 heterojunction demonstrated superior antimicrobial efficacy against both Gram-positive and Gram-negative bacteria. Additionally, it enhanced the photocatalytic degradation of the methyl orange and effectively removed oxidizable impurities from pharmaceutical effluent while maintaining good recycling capacity. The photocatalytic degradation of methyl orange obeyed the pseudo-first-order reaction dynamics model and showed a strong influence of the CdS amount on the degradation. The maximum degradation rate for methyl orange dye using the CdS/TiO2 Janus membrane was 0.057 min−1, which was 3.5 times that of the TiO2 membrane. The degradation efficiency of CdS/ TiO2 was found to be up to 96.8% in 60 minutes and showed excellent photocatalytic activity in five consecutive cycles. The chemical oxygen demand (COD) removal efficiency for the TiO2 membrane was 74.16, which was increased to 91.66% for the CdS/TiO2 membrane. This study provides insight into developing highly efficient Janus inorganic nanofiber with superior structural integrity for waste water treatment and environmental remediation.

New breakthrough in dye removal: Ultrafast removal of high concentration MB with biochar-based organic photocatalysts under indoor light (30W/m2) drive

At the present stage, the light sources used in the photocatalytic degradation of organic pollutants are generally UV and simulated sunlight, which invariably increase the extra energy loss. Therefore, it is important to find an effective strategy for the rapid removal of high concentrations of organic pollutants in a cleaner and low-light environment with lower energy consumption. Here we prepare three biochar-based organic photocatalytic materials PM6:TPIC/BC, PM6:TPIC-2Cl/BC, PM6:TPIC-4Cl/BC by impregnation method. Among the three photocatalysts, PM6:TPIC-4Cl/BC exhibits the highest apparent rate constant (0.105 min−1), which is 3 times and 1.5 times higher than PM6:TPIC/BC (0.034 min−1) and PM6:TPIC-2Cl/BC (0.071 min−1) respectively. Due to a wider range of light absorption, the best material is able to completely degrade high concentrations of MB in 3 min. Moreover, photoluminescence (PL), time-resolved photoluminescence (TRPL), electrochemical impedance (EIS), and photocurrent (PCR) measurements confirm its exceptional photogenerated electron-hole separation. Free radical trapping identifies h+, ·OH, and ·O2− as key reaction species. DFT analysis reveal atoms with higher Fukui index (f0) as prime free radical targets. LC-MS detects intermediates, suggesting possible degradation pathways. The reduced toxicity of the degradation products after photocatalysis indicates an environmentally friendly approach. This work demonstrates the valuable of PM6:TPIC-4Cl/BC organic photocatalysts for treating organic wastewater.