Interfacial Charge Separation Research Articles

Fluoride Ions Post-Treatment Regulates Interfacial Charge Separation and Transport to Promote Solar Water Splitting of Bismuth Vanadate.

Herein, we propose a simple and effective fluoride (F-) ions post-treatment method to improve the solar water splitting performance of BVO. The surface modification of BVO with functional F- ions not only facilitates the transfer and separation efficiency of carriers at the electrode/electrolyte interface but also promotes the adsorption and activation of water, resulting in a photocurrent of 3.2 mA/cm2 at a bias voltage of 1.2 VRHE. Furthermore, the transfer and separation of carriers in the bulk and on the surface are further regulated by the oxygen vacancies induced by F- ions, thereby enhancing the PEC water splitting performance of BVO. Notably, the experimental findings demonstrate that the inclusion of F- ions in the KBi electrolyte enhances the photo-charging process of BVO. Specifically, at a bias voltage of 0.6 VRHE, the BVO-0.12F sample exhibits a stable photocurrent of 1.2 mA/cm2, which is twice as high as that of the initial BVO sample. Remarkably, our study unveils that the addition of F- ions into the KBi electrolyte solution plays a pivotal role in facilitating the separation of charge carriers and promoting interfacial charge transport. Consequently, this further leads to a substantial enhancement in the solar water splitting performance for BVO-0.12F photoanode.

Hollow SrTiO3 photocatalyst with spatially separated OER and HER cocatalysts for photocatalytic overall water splitting

Overcoming the challenge of sluggish charge separation and the concurrent occurrence of overall water splitting (OWS) half reactions at the same catalytic sites is crucial for achieving efficient photocatalysis. This issue often leads to a high recombination rate and the back reaction of OWS. In this study, we addressed this challenge by enhancing interfacial spatial charge separation. Specifically, we designed hollow SrTiO3 spheres and spatially segregated the hydrogen and oxygen evolution sites on the outer and inner surfaces, respectively, for OWS. The spatially distributed Pt/SrTiO3/CoOx catalysts exhibited exceptional separation of photogenerated charges, resulting in 3-times higher stoichiometric OWS compared to Pt/SrTiO3. This work underscores the effectiveness of a well-tailored spatially distributed structure in promoting charge separation in photocatalysis, thereby opening avenues for the development of efficient artificial photosynthesis systems.

Visible light driven Z-scheme α-MnO2 (1D)/Bi7O9I3 (2D) heterojunction photocatalyst for efficient degradation of bisphenol A in water

Z-scheme heterojunctions are gaining attention for their outstanding photocatalytic performance in degrading organic pollutants due to improved charge separation efficiency. In view of this, the present study is focused on the synthesis of novel 3D α-MnO2/Bi7O9I3 (MB) nanocomposites heterojunctions of varying α-MnO2 contents via facile in-situ chemical precipitation method at room temperature. Under optimum conditions, MB4 (comprising 485 mg of α-MnO2) exhibited exceptional performance, achieving about 97.5% of bisphenol A (BPA) degradation in 80 mins with a degradation rate constant of 0.08354 min−1. Such superior performance is attributed to efficient interfacial integration and charge separation, validated through various characterization techniques. Further, MB4 heterojunction facilitated Z-scheme electron-hole pair transfer and exhibited an augmented specific surface area. The active species involved in the degradation of BPA were identified as •O2– and •OH in scavenging experiments and supported by findings based on EPR. Additionally, degradation pathways and plausible BPA intermediates have been proposed based on LC-MS/MS studies. Furthermore, with an impressive mineralization rate (89.5%), the toxicity study unveiled less harmful intermediates than the parent compound BPA. MB4 photocatalyst also exhibited commendable stability, as evidenced by its studies based on five reuse cycles with 92.9% efficiency. In essence, visible-light-driven Z-scheme α-MnO2/Bi7O9I3 heterojunction photocatalyst offered a simple and sustainable approach for producing environmentally friendly materials, underscoring its potential in the removal of BPA in water and wastewater treatment.

Fabrication of piezotronic ZnO p-n homojunction via metal/oxygen defects modulation for efficient photoelectrocatalysis

Homojunction is a viable alternative strategy to realize excellent charge separation for enhancing photoelectrocatalytic performance. However, the feasible regulation of the homojunction interface remains challenging. Herein, a ZnO n-p homojunction with the piezotronic effect is constructed via an in-situ solvothermal method for enhancing photoelectrocatalytic activity. ZnO nanorods are transformed from n-type to p-type ZnO nanoparticles with zinc vacancies, leading to the n-p homojunction. The optimal NPZ-36 exhibits a superior photocurrent density of 1.56 mA/cm2 at 1.23 V vs. RHE and a high incident photon to current conversion efficiency of 75 % at 360 nm. Impressively, with the merits of inherent piezoelectric and photocatalytic properties of wurtzite ZnO, the piezoelectric-enhanced photoelectrochemical activity originates from the simultaneous promotion of bulk charge transfer and interfacial charge separation in ZnO n-p homojunction. The photocurrent density of NPZ-36–900 can reach to 2.02 mA/cm2 under the stirring rate of 900 rpm, which is 2.1 times higher than that of pure ZnO photoanode.

Expression of Concern: High interfacial charge separation in visible-light active Z-scheme g-C3N4/MoS2 heterojunction: Mechanism and degradation of sulfasalazine

Expression of Concern: High interfacial charge separation in visible-light active Z-scheme g-C3N4/MoS2 heterojunction: Mechanism and degradation of sulfasalazine

Carbon quantum dots/BiVO4 S-scheme piezo-photocatalysts improved carrier separation for efficient antibiotic removal

Reasonable design of an efficient S-scheme photocatalyst remains an ongoing challenge due to the limitation of interfacial charge separation efficiency. Herein, CQDs/BiVO4 S-scheme heterojunction with Bi–O–C bond was synthesized by introducing carbon quantum dots (CQDs) growth on BiVO4 piezo-photocatalyst and absorbed visible light up to 750 nm. Under light + ultrasonic conditions, the reaction rate constant (k) of BVO/C-0.10 reached 0.0517 min−1 on tetracycline (TC) degradation, which was 2.24 and 4.04 times higher than those of BiVO4 and CQDs, respectively. The enhanced performance was attributed to the improved efficiency of the photogenerated carrier separation, originating from the combination of piezoelectric effect and S-scheme heterojunction with Bi–O–C bond. The Bi–O–C bond at the CQDs (3–8 nm) and BiVO4 interfaces connected the two semiconductor materials and provided an atomic-level interface channel for carrier migration. The piezoelectric properties of the composites were investigated by piezo−response force microscopy (PFM). Based on Mott−Schottky curves, X-ray photoelectron spectroscopy (XPS), and scavenging experiments, the possible piezo-photocatalytic mechanism was proposed in combination with the band structures and characteristics of CQDs and BiVO4. This work furnishes unique insights into developing efficient S-scheme piezo-photocatalysts for purifying wastewater.

MoB2 modified g-C3N4: A Schottky junction with enhanced interfacial redox activity and charge separation for efficient photocatalytic H2 evolution

The g-C3N4 material, which exhibits a sensitivity to visible light and has a band position that is appropriate for the photoreduction of H2, has garnered significant interest. However, the ability of g-C3N4 to use light for photocatalysis is restricted due to its insufficient capacity to absorb light and its poor reaction kinetics on the surface. The researchers opted for the metallic MoB2 to create a Schottky junction coupled with g-C3N4. The incorporation of MoB2 nanoparticles onto g-C3N4 enhances its light absorption capacity and promotes the efficient separation and transfer of photogenerated charge. In addition, MoB2 nanoparticles served as active sites to accelerate H2 evolution. Compared to g-C3N4, the MoB2@g-C3N4 composite exhibited a nearly 51-fold increase in H2 production rate, indicating a significant improvement in photocatalytic activity. The present investigation demonstrated the potential of metallic MoB2 as a modified material during a photocatalytic H2 evolution reaction.

Visible-Light-Driven Inactivation of Bacteria and H2 Generation Catalyzed by Oxygen-Vacancy-Rich One-Dimensional/Two-Dimensional W18O49/g-C3N4 Z-Scheme Heterostructures.

Z-scheme heterostructure-based photocatalysts consist of a reduction photocatalyst and an oxidation photocatalyst, enabling them to possess a high capacity for both reduction and oxidation. However, the coupling reaction between photocatalytic H2 generation through water reduction and sterilization using Z-scheme systems has been rarely reported. Herein, 1D W18O49 nanowires embedded over 2D g-C3N4 nanosheets are well-constructed as an integrated Z-scheme heterojunction. Experimental results and density functional theory calculations not only demonstrate the achievement of efficient interfacial charge separation and transport, leading to prolonged lifetime of photogenerated charge carriers, but also directly confirm the mechanism of Z-scheme charge transfer. As expected, the optimized W18O49/g-C3N4 nanostructure exhibits superior photocatalytic sterilization activity against Staphylococcus aureus as well as excellent H2 generation performance under visible-light irradiation (λ ≥ 420 nm). Due to its nontoxic nature, W18O49/g-C3N4 holds great potential in eradicating bacterial infections in living organisms.

Enhanced peroxymonosulfate activation by S-scheme AgI/Cu-BiVO4 heterojunction for efficient photocatalytic organics degradation and Microcystis aeruginosa inactivation: Performance, interfacial engineering and mechanism insight

Novel oxygen vacancies-enriched AgI/Cu-BiVO4 (ACBV) S-scheme heterojunction catalysts were constructed to boost photocatalytic organics degradation and M. aeruginosa inactivation with peroxymonosulfate (PMS) assistance. Specific interfacial charge transfer and abundant active centers were guided by introducing Cu doping and AgI coupling into BiVO4, with the catalytic activity and mechanism systematically investigated. The optimal 0.25-ACBV heterojunction exhibited 97.6% tetracycline (TC) degradation under PMS-assisted visible light and achieved effective inactivation of M. aeruginosa within 20 min (78.8%). The S-scheme heterostructure from Cu-BiVO4 to AgI and synergistic effects endowed the system with high-energy carrier transfer kinetics and strong oxygen reduction capability. Meanwhile, the redox cycling of Cu2+/Cu+ and surface oxygen defects served as electron acceptors to accelerate interfacial charge separation and as adsorption activation sites for PMS, promoting efficient mass transfer in the non-homogeneous system. This study inspires the design of high-performance S-scheme photocatalytic activators and expands their potential applications in environmental remediation.

Construction of BiVO4/BiOCl photoelectrochemical sensor for rapid detection of dopamine

This paper reports the preparation of BiVO4/BiOCl heterojunction photobiosensors with high sensitivity, stability and selectivity for detecting changes in dopamine concentration. BiVO4 with nanostructures was prepared by electrostatic spinning, however, BiVO4 semiconductor material is susceptible to complex inhibition of photogenerated carriers due to structural defects affecting the detection performance of the sensor, in order to solve this problem, BiVO4/BiOCl heterogeneous structures were prepared by hydrothermal synthesis. Not only the result of improving the interfacial charge separation efficiency, the photocurrent density was increased to 0.4 μA, but also the high sensitivity of the BiVO4/BiOCl heterojunction photovoltaic material for the detection of dopamine was improved. The linear response range for dopamine detection was 1-13 μM (R2 = 0.99079) and the detection limit was 0.134 μM (S/N = 3). In addition, selective detection was achieved in the presence of a number of common interferences within human plasma, and the photocurrent response was tested for stability after sustained visible light irradiation.

Revealing the lattice engineering of Delafossite in core–shell CuRhO2@CuGaO2 heterostructure for efficient visible light photocatalytic activity

The establishment of heterojunctions at phase interfaces represents a pivotal strategy for enhancing photocatalytic performance. However, the inferior interfacial contact caused by the mismatch of crystal structure or lattice parameters seriously hampers the rapid and smooth migration of charge carriers in traditional heterojunctions. In this work, a tightly integrated Delafossite-based core–shell CuRhO2@CuGaO2 heterojunction was judiciously designed and constructed via a hydrothermal approach. Experimental and density-functional theory calculation results co-unravel that the built-in electric field is established in the lattice-matched heterogeneous interfaces, thereby providing smooth interface charge separation and transfer via the Z-scheme pathways. Benefitting from the heterojunction effect and unique core–shell coupling architecture, the strong visible light absorption and fast spatial charge transfer are realized in the CuRhO2@CuGaO2 heterostructure. The photocurrent density of the CuRhO2@CuGaO2 heterojunction is nearly 1.25 and 3.75 times those of pristine CuRhO2 and CuGaO2, respectively. As a result, the CuRhO2@CuGaO2 heterostructure reveals an excellent photocatalytic degradation rate of tetracycline hydrochloride, achieving a 3.02 and 2.38-fold improvement than those of the CuRhO2 and CuGaO2, respectively. This work is expected to pave the way for novel insights into the design of efficient heterojunction photocatalysts to steer the rapid photocarrier flows across the heterointerface.

Boosting photocatalytic NO oxidation mediated by high redox charge carriers from visible light-driven C3N4/UiO-67 S-scheme heterojunction photocatalyst

The construction of CN/UiO-67 (CNU) S-scheme heterojunction composites through in situ formation of UiO-67 on carbon nitride (C3N4) helps to address the limitations of carbon nitride (CN) in photocatalytic NO elimination. The optimized CNU3 demonstrates superior photocatalytic efficiency, which is attributed to electronic channels constructed by Zr-N bonds and S-scheme electron transport mechanism, effectively promoting the efficient separation of photogenerated charge carriers with high redox potentials. Density Functional Theory (DFT) calculations reveal redistributed electronic orbitals in CNU3, with progressive and continuous energy levels near the Fermi level, which bolsters electronic conduction. Comprehensive quenching experiments, Electron Paramagnetic Resonance (EPR), and in situ Diffuse Reflectance Infrared Fourier Transform Spectroscopy (DRIFTS) analyses highlight a synergistic interplay of electrons, holes, and superoxide radicals in CNU3, inhibiting the generation of toxic nitrogen oxide intermediates and culminating in highly efficient photocatalytic NO oxidation. This study not only elucidates the mechanisms underpinning the enhanced performance of CNU3 heterojunctions but also offers new perspectives on the preparation and interfacial charge separation of heterojunction photocatalysts.

P-N Bonds-Mediated Atomic-Level Charge-Transfer Channel Fabricated between Violet Phosphorus and Carbon Nitride Favors Charge Separation and Water Splitting.

Heterostructures are widely employed in photocatalysis to promote charge separation and photocatalytic activity. However, their benefits are limited by the linkages and contact environment at the interface. Herein, violet phosphorus quantum dots (VPQDs) and graphitic carbon nitride (g-C3 N4 ) are employed as model materials to form VPQDs/g-C3 N4 heterostructures by a simple ultrasonic pulse excitation method. The heterostructure contains strong interfacial P-N bonds that mitigate interfacial charge-separation issues. P-P bond breakage occurs in the distinctive cage-like [P9] VPQD units during longitudinal disruption, thereby exposing numerous active P sites that bond with N atoms in g-C3 N4 under ultrasonic pulse excitation. The atomic-level interfacial P-N bonds of the Z-scheme VPQDs/g-C3 N4 heterostructure serve as photogenerated charge-transfer channels for improved electron-hole separation efficiency. This results in excellent photocatalytic performance with a hydrogen evolution rate of 7.70mmolg-1 h-1 (over 9.2 and 8.5 times greater than those of pure g-C3 N4 and VPQDs, respectively) and apparent quantum yield of 11.68% at 400nm. Using atomic-level chemical bonds to promote interfacial charge separation in phosphorene heterostructures is a feasible and effective design strategy for photocatalytic water-splitting materials.

Highly sensitive hybrid silicon carbonitride piezoresistive sensors enabled by coupling piezoelectric effect

Piezoresistive sensors with high working temperature and excellent sensitivity are highly desired for in-situ measuring pressure in various high temperature applications. Polymer-derived silicon carbonitrides (SiCNs) are a novel class of materials with excellent stability and piezoresistive performance at high temperature, yet challenging to build to meet the rapid growth of large-area electronics. This work demonstrates a thin and highly sensitive hybrid SiCN piezoresistive films enabled by coupling piezoelectric effect of Al-doped ZnO (AZO). The hybrid thin films with the optimal nano-domain phase of SiCN features ultrahigh gauge factors of 6518 to 31,195 upon various compressive stresses, which are significantly larger than those of single-layer SiCN and other existing piezoresistive materials. First-principles calculations reveal that the charges from AZO layer accumulate and move toward the carbon clusters in SiCN under compressive stress, resulting in greater tunneling currents between carbon clusters and more significant piezoresistive effect. Moreover, superior piezoresistive performance of the optimal hybrid system can be characterized by atomic-scale binding energy and band gap change, as formation of the hybrid structure facilitates interfacial charge separation and increases density of electron at conduction band. This work opens an avenue for improving sensitivity of piezoresistive sensors by effective coupling of piezoelectric materials.

Enhanced Photocatalytic Properties of All-Organic IDT-COOH/O-CN S-Scheme Heterojunctions Through π-π Interaction and Internal Electric Field.

Herein, we present a distinct methodology for the in situ electrostatic assembly method for synthesizing a conjugated (IDT-COOH)/oxygen-doped g-C3N4 (O-CN) S-scheme heterojunction. The electron delocalization effect due to π-π interactions between O-CN and self-assembled IDT-COOH favors interfacial charge separation. The self-assembled IDT-COOH/O-CN exhibits a broadened visible absorption to generate more charge carriers. The internal electric field between the IDT-COOH and the O-CN interface provides a directional charge-transfer channel to increase the utilization of photoinduced charge carriers. Moreover, the active species (•O2-, h+, and 1O2) produced by IDT-COOH/O-CN under visible light play important roles in photocatalytic disinfection. The optimum 40% IDT-COOH/O-CN can kill 7-log of methicillin-resistant Staphylococcus aureus (MRSA) cells in 2 h and remove 88% tetracycline (TC) in 5 h, while O-CN only inactivates 1-log of MRSA cells and degrades 40% TC. This work contributes to a promising method to fabricate all-organic g-C3N4-based S-scheme heterojunction photocatalysts with a wide range of optical responses and enhanced exciton dissociation.

Construction of NiS/MnCdS S-scheme heterojunction for efficient photocatalytic overall water splitting: Regulation of surface sulfur vacancy and energy band structure

The overall water splitting based on specific photocatalysts is one of the ultimate ways to solve the energy and environmental crisis facing humanity. Sulfide photocatalysts have greater potential in photocatalytic production of solar fuel. However, due to its easy photocorrosion phenomenon, it not effectively driving the water oxidation semi-reaction to produce oxygen, so how to use sulfide photocatalyst to decompose pure water to achieve stoichiometric reaction of H2/O2 production remains a quite challenging task. Herein, sulfur vacancies-rich MnCdS nanoparticles were modified with NiS nanosheets through the hydrothermal derivation method. Different concentration gradients of sulfur-vacancy in MnCdS nanoparticles (MnCdS-Vs-X) with tunable band structures were successful prepared by regulating the concentration of hydrazine hydrate, thus improves the efficiency of light energy utilization and charge separation and the existence of S defects was verified by transmission electron microscopy (TEM) and electron paramagnetic resonance (EPR). The density function theory (DFT) calculation bears out that the draw into of S vacancy adjusted the band structure of MnCdS. Moreover, the successful construction of an S-scheme heterojunction between NiS and MnCdS-Vs-3 has been strongly demonstrated by in-situ XPS and UPS, which promoted interfacial charge separation and further improved the photocatalytic hydrogen evolution efficiency. The as-obtained S-scheme 20 %NiS/MnCdS-Vs-3 heterojunction exhibit excellent visible-light H2 production activity of 4099.55 μmol g−1h−1, 6.75 times higher than pure MnCdS. Most importantly, the excellent and stable photocatalytic overall water splitting activity of H2-509.70 μmol g-1h−1/O2-254.90 μmol g-1h−1 were obtained over 20 % NiS/MnCdS-Vs-3, which further demonstrates the application value of NiS/MnCdS-Vs-3 photocatalysts. This work proposes new ideas for the application of S-vacancies and S-scheme heterojunction in addressing the stability issues associated with sulfide-based photocatalysts in photocatalytic water splitting.

In situ irradiated XPS investigation on S-scheme TiO2/Bi2S3 photocatalyst with high interfacial charge separation for highly efficient photothermal catalytic CO2 reduction

The combination of S-scheme heterojunction and photothermal effect is a promising strategy to achieve efficient CO2 photoreduction into solar fuel due to the boosted charge carrier separation efficiency and faster surface reaction rate. Herein, unique photothermal-coupled TiO2/Bi2S3 S-scheme heterojunction nanofibers were fabricated and applied to a full-spectrum CO2 photoreduction system. Density functional theory calculation and experimental analyses have confirmed the generation of the internal electric field and the S-scheme electron transfer pathway, leading to a highly efficient charge carrier separation. Thanks to the excellent photothermal conversion capacity of Bi2S3, the photogenerated electron transfer rate, and surface reaction rate were further accelerated in hybrid photocatalysts. Under the synergistic effect of S-scheme heterojunction and photothermal effects, the optimal TiO2/Bi2S3 nanofibers achieved 7.65 μmol h–1 of CH4 production rate, which is 5.24 times higher than that of pristine TiO2. Moreover, the morphology reconstruction of Bi2S3 in hybrids facilitates the CH4 selectivity was significantly improved from 64.2% to 88.7%. Meanwhile, the CO2 photoreduction reaction route over TiO2/Bi2S3 nanofibers was investigated based on in-situ Fourier transform infrared spectra. This work provides some useful hints for designing highly efficient photothermal-coupled photocatalysts for CO2 photoreduction.

Dynamic in situ Formation of Cu2O Sub‐Nanoclusters through Photoinduced pseudo‐Fehling's Reaction for Selective and Efficient Nitrate‐to‐Ammonia Photosynthesis

AbstractCopper (Cu) is evidenced to be effective for constructing advanced catalysts. In particular, Cu2O is identified to be active for general catalytic reactions. However, conflicting results regarding the true structure‐activity correlations between Cu2O‐based active sites and efficiencies are usually reported. The structure of Cu2O undergoes dynamic evolution rather than remaining stable under working conditions, in which the actual reaction cannot proceed over the prefabricated Cu2O sites. Therefore, the dynamic construction of Cu2O active sites can be developed to promote catalytic efficiency and reveal the true structure‐activity correlations. Herein, by introducing the redox pairs of Cu2+ and reducing sugar into a photocatalysis system, it is clarified that the Cu2O sub‐nanoclusters (NCs), working as novel active sites, are on‐site constructed on the substrate via a photoinduced pseudo‐Fehling's route. The realistic interfacial charge separation and transformation capacities are remarkably promoted by the dynamic Cu2O NCs under the actual catalysis condition, which achieves a milestone efficiency for nitrate‐to‐ammonia photosynthesis, including the targets of production rate (1.98±0.04 mol gCu−1 h−1), conversion ratio (94.2±0.91 %), and selectivity (98.6 %±0.55 %). The current work develops an effective strategy for integrating the active site construction into realistic reactions, providing new opportunities for Cu‐based chemistry and catalysis sciences research.

Dynamic in situ Formation of Cu2 O Sub-Nanoclusters through Photoinduced pseudo-Fehling's Reaction for Selective and Efficient Nitrate-to-Ammonia Photosynthesis.

Copper (Cu) is evidenced to be effective for constructing advanced catalysts. In particular, Cu2 O is identified to be active for general catalytic reactions. However, conflicting results regarding the true structure-activity correlations between Cu2 O-based active sites and efficiencies are usually reported. The structure of Cu2 O undergoes dynamic evolution rather than remaining stable under working conditions, in which the actual reaction cannot proceed over the prefabricated Cu2 O sites. Therefore, the dynamic construction of Cu2 O active sites can be developed to promote catalytic efficiency and reveal the true structure-activity correlations. Herein, by introducing the redox pairs of Cu2+ and reducing sugar into a photocatalysis system, it is clarified that the Cu2 O sub-nanoclusters (NCs), working as novel active sites, are on-site constructed on the substrate via a photoinduced pseudo-Fehling's route. The realistic interfacial charge separation and transformation capacities are remarkably promoted by the dynamic Cu2 O NCs under the actual catalysis condition, which achieves a milestone efficiency for nitrate-to-ammonia photosynthesis, including the targets of production rate (1.98±0.04 mol gCu -1 h-1 ), conversion ratio (94.2±0.91 %), and selectivity (98.6 %±0.55 %). The current work develops an effective strategy for integrating the active site construction into realistic reactions, providing new opportunities for Cu-based chemistry and catalysis sciences research.

Facile green synthesis route for new ecofriendly photo catalyst for degradation acid red 8 dye and nitrogen recovery

This study novelty is that new photo catalyst prepared from sustainability low cost precursors. Dark red color hydrogel composites have been easily prepared from gelatin biopolymer using a simple sol–gel method. Gelatin doped by cobalt chloride, and silver nanoparticles (SNPs) in the presence of traces amount of sodium dodecyl sulfate surfactant and calcium chloride. Water-insoluble Gelatin composites are thermally stable photocatalysts for the degradation of toxic anionic acid red 8 dye. Promising photodynamic activity confirmed by fluorescence emission at λmax 650 nm. Optical absorption in Vis. light enhanced photo catalytic activity. Silver nanoparticles enhanced crystallinity, and improved optical properties and porosity. Dopants by CoCl2 and silver nanoparticles increased band gap of gelatin composites from (1.82 to 1.95) indicating interfacial charge separation. Low band gaps improved photo catalytic activity. Optical band gaps (Eg) lower than 2.0 eV indicates high catalytic activity in the photo degradation acid red 8 dye using Vis. light, wavelength 650 nm. Percent removal efficiency (%Re) of the dye at 500 ppm initial concentration, pH 1, contact time 30 min., and 0.20 g L−1 dose photo catalyst reached 95%. pH not affects removal efficiency. So, gelatin composites removed AR8 dye by photodegradation mechanism rather than adsorption due to photodynamic activity. Kinetics of photodegradation followed pseudo first order kinetic with rate constant k1 5.13 × 10−2 min.−1 Good electrical conductivity and magnetic properties (effective magnetic moment (µeff 4.11 B.M) improved dye degradation into simple inorganic species. Nutrients NH4+, and NO3− degradation products recovered by using alumina silicate clay via a cation exchange mechanism.