Organic pollutants owing to their high toxicity and resistance present a significant environmental challenge. To mitigate this issue, a visible-light-responsive perovskite-based metal free graphitic carbon nitride functionalized with rGO was hydrothermally developed. The developed materials were characterized by standard analytical techniques such as UV-Vis DRS, XRD, FTIR, SEM, FESEM, HRTEM, BET, XPS, and EDX-mapping. The characterization results demonstrate the successful construction of nanohybrid photocatalysts with well-integrated interfaces among pristine materials, which results in significantly improved photocatalytic activity. The photo-catalytic degradation study was evaluated using all the synthesized materials, whereas, 10 wt% CoTiO3/rGO/g-C3N4 (10CGG) nanohybridrevealed superior photocatalytic performance, achieving 95% degradation ofrhodamine B in 30 min and 93.5% degradation of 4-nitrophenol in 125 min under visible light.Additionally, the photocatalytic efficiency of 10CGG nanohybrid was further confirmed by phototransformation of 2,4,6-trichlor-ophenol and mineralization study. The mechanistic insights were supported by radical quenching experiments, terephthalic acid versus NaOH and NBT tests. The enhanced photocatalytic performance is attributed to more efficient separation of photoinduced electron (e-)-hole (h+) pairs. Consequently, a direct S-scheme mechanism was proposed to explain efficient charge carrier separation for improved photocatalytic outcomes, which was further supported by PL, EIS, Mott-Schottky and ESR results.

With the growing threat of organic pollutants in water bodies, there is an urgent need for sustainable and efficient water decontamination methods. This research focused on synthesizing a novel Z-scheme ternary heterostructure composed of graphene oxide (GO)-mediated polyaniline (PANI) with alpha-Fe2O3 and investigated its potential in brilliant green (BrG) and ciprofloxacin (CIP) degradation tests under visible light. The ternary composite demonstrated exceptional photocatalytic activity, with the optimized 10%PANI/GO/alpha-Fe2O3 (10PGF) photocatalyst achieving 99.8% degradation of BrG in 25 min and 93% degradation of CIP in 90 min of irradiation. The 10PGF composite achieved rate constants of 0.222 min-1 for BrG and 0.0295 min-1 for CIP. The rate constant for BrG degradation was 15 and 10 times faster than that for PANI and alpha-Fe2O3, respectively, while CIP was degraded 8.9 and 6.1 times faster. The degradation of the pollutants was facilitated by both O2(center dot)- and (OH)-O-center dot, as confirmed by capturing active species, a nitroblue tetrazolium test and use of a PL terephthalic acid probe. The proposed Z-scheme mechanism elucidated charge carrier movements and active species involvement, revealing the enhanced photocatalytic performance of the ternary composite. The 10PGF ternary composite demonstrated exceptional recyclability over five repeated cycles, with XRD analysis confirming no structural changes in the material. Moreover, adsorption studies were also performed, which showed a strong correlation (R2 = 0.974) with Langmuir isotherms and that pseudo-second order kinetics was followed.

To develop an efficient visible light responsive photocatalyst remains a major challenge for sustainable wastewater purification. In this work, a novel erbium-doped graphitic carbon nitride (Er-g-C3N4) supported with silver indium sulfide (AgInS2) heterocomposite was rationally designed via a solid-state hydrothermal approach to overcome the limitations of poor charge separation and narrow light absorption in conventional photocatalysts. The introduction of Er3+ ions and the formation of an intimate heterocomposite synergistically enhanced visible light harvesting and charge carrier migration, leading to superior photocatalytic efficiency. Comprehensive structural and optical analyses (XRD, XPS, FTIR, BET, and UV-Vis DRS) confirmed successful integration and improved surface properties. Cyclic voltammetry revealed enhanced redox capability, while radical trapping experiments identified superoxide radicals and photogenerated holes as the main reactive species responsible for pollutant degradation. The optimized 6 wt.% of heterocomposite (6 wt.% AgInS2/Er-g-C3N4) exhibited exceptional photodegradation and mineralization performance against methylene blue (MB) dye, tetracycline (TC), and oxytetracycline (OTC) antibiotics under visible light irradiation. Mechanistic investigations, supported by photoluminescence quenching, impedance spectroscopy, and radical scavenging tests, revealed that enhanced redox activity and efficient electron-hole separation primarily drive the photocatalytic process. The remarkable activity of the 6 wt.% AgInS2/Er-g-C3N4 heterocomposite in real wastewater highlights its potential as a promising and scalable material for practical environmental remediation applications.

This study explores the synthesis, characterization and dual functionality of a binary NiFe-LDH/BiOBr (NFB) heterostructure for the removal of organic pollutants from aqueous suspensions. The NFB heterostructure was synthesized using a sol-gel method with varying mass ratios of NiFe-LDH, resulting in a material with outstanding photodegradation and adsorption efficiency. Under visible light, the 8NFB (8 wt% NiFe-LDH/BiOBr) achieved up to 99.0 % degradation of Rhodamine B (RhB) and 90.0 % degradation of tetracycline hydrochloride (TC), under conditions optimized through response surface methodology (RSM), indicating remarkable improvement in degradation efficiencies compared to bare BiOBr (49.1 % and 35.7 % for RhB and TC, respectively) and NiFe-LDH (34.7 % and 25.4 % for RhB and TC, respectively). Mechanistic analysis attributed this enhanced performance to improved charge separation, effective light absorption, and increased generation of reactive oxygen species (ROS), all facilitated by the Z-scheme heterojunction. Trapping experiments confirmed that hydroxyl radicals (center dot OH) and superoxide anions (O2 center dot- ) were key contributors to the degradation process. The degradation was fairly fast with apparent rate constants (k) being 0.148 min-1 and 0.036 min-1 for RhB and TC, respectively. Additionally, adsorption isotherm studies revealed that the Langmuir isotherm model (R2 = 0.9897, reduced chi 2 = 0.1762) best described the RhB adsorption onto 8NFB, suggesting monolayer adsorption. The adsorption kinetic data aligned well (R2 = 0.9999, reduced chi 2 = 1.5 x 10-4) with the pseudo-second-order (PSO) model signifying chemical adsorption of RhB. The composite also demonstrated excellent photostability and reusability, maintaining high performance up to five cycles.

Semiconductor-mediated photocatalytic technology has emerged as a promising strategy for wastewater remediation. Among various photocatalysts, graphitic carbon nitride motifs─metal-free and two-dimensional triazine-based polymers have attracted significant research interest due to their multifunctional characteristics. In this study, a nitrogen-enriched form of graphitic carbon nitride (g-C3N5), featuring a lower C/N ratio and an additional triazole moiety replacing the conventional triazine unit, was synthesized via thermal polymerization of 3-amino-1H-1,2,4-triazole. Subsequently, its heterostructure was strategically engineered by incorporating highly crystalline silver iodide (AgI) nanoparticles through a facile solid-state approach. Physicochemical characterizations confirmed the crystalline, porous, and visible-light-responsive nature of the fabricated heterostructured semiconducting material (AgI/g-C3N5 or AICN). The enhanced charge separation efficiency of the heterostructure was evidenced by photoluminescence analysis and further supported by electrochemical investigations. Comprehensive photocatalytic degradation experiments using Rhodamine B (RhB), a chromophoric dye, and chloramine T (CT), a drug derivative, revealed that the 20 wt % AgI/g-C3N5 composite (20AICN) exhibited the highest photocatalytic efficiency among the series of fabricated photocatalysts─achieving 96.5% degradation of RhB and 82.8% degradation of CT within 24 and 120 min of visible-light irradiation, respectively. Process optimization using Box-Behnken Design and Response Surface Methodology identified the optimal operational parameters: 10 ppm pollutant concentration, 1 g L- 1 photocatalyst dose, and neutral pH 7, with respective irradiation times of 24 min (RhB) and 120 min (CT). A strong correlation was observed between experimental and predicted outcomes (R2 > 0.991). Kinetic analysis demonstrated that the degradation followed pseudo-first-order kinetics, and mineralization studies revealed over 50% TOC removal of these pollutants. Recyclability tests confirmed the excellent photostability of the 20AICN photocatalyst, showing insignificant photocorrosion after seven consecutive photocatalytic cycles. Scavenging experiments identified superoxide radicals (O2•-) and photogenerated holes (h+) as the dominant reactive species responsible for the degradation. These findings, along with Mott-Schottky analysis, supported a type-II heterojunction photocatalytic mechanism governing the degradation process.

A highly effective and unique AgBr-NiO binary heterojunction was developed using an effective one-pot sol-gel method. The physicochemical properties of the produced materials were carefully examined using analytical techniques, including X-ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive X-ray (EDX) analysis, transmission electron microscopy (TEM), Brunauer-Emmett-Teller (BET), ultraviolet-visible diffuse reflectance spectroscopy (UV-vis-DRS), Fourier transform infrared spectroscopy (FTIR), and photoluminescence (PL). The mesoporous nature and high surface properties of AgBr-NiO were revealed by the BET analysis. The AgBr-NiO composite showed greater photocatalytic degradation efficiency than bare AgBr and NiO when exposed to visible light for the colored anionic dye rhodamine B (RhB) and bisphenol A (BPA), a colorless endocrine-disrupting contaminant (EDC), resulting in high photocatalytic activity for the degradation of RhB (97.6% in 11 min) and BPA (85% in 120 min). Additionally, a notable decrease in TOC over time was observed under similar reaction conditions in the photo-mineralization examination of both model pollutants. Trapping tests were conducted to determine which reactive oxygen species (ROS) were involved in the degradation process. A plausible Z-scheme mechanism for this n-p heterojunction was proposed to explain the formation of e-/h+ pairs induced by visible light. The proposed work facilitates the development of a recyclable photocatalyst characterized by high biological activity and low toxicity.

To develop an efficient visible light responsive photocatalyst remains a major challenge for sustainable wastewater purification. In this work, a novel erbium‐doped graphitic carbon nitride (Er‐g‐C 3 N 4 ) supported with silver indium sulfide (AgInS 2 ) heterocomposite was rationally designed via a solid‐state hydrothermal approach to overcome the limitations of poor charge separation and narrow light absorption in conventional photocatalysts. The introduction of Er 3+ ions and the formation of an intimate heterocomposite synergistically enhanced visible light harvesting and charge carrier migration, leading to superior photocatalytic efficiency. Comprehensive structural and optical analyses (XRD, XPS, FTIR, BET, and UV–Vis DRS) confirmed successful integration and improved surface properties. Cyclic voltammetry revealed enhanced redox capability, while radical trapping experiments identified superoxide radicals and photogenerated holes as the main reactive species responsible for pollutant degradation. The optimized 6 wt.% of heterocomposite (6 wt.% AgInS 2 /Er‐g‐C 3 N 4 ) exhibited exceptional photodegradation and mineralization performance against methylene blue (MB) dye, tetracycline (TC), and oxytetracycline (OTC) antibiotics under visible light irradiation. Mechanistic investigations, supported by photoluminescence quenching, impedance spectroscopy, and radical scavenging tests, revealed that enhanced redox activity and efficient electron–hole separation primarily drive the photocatalytic process. The remarkable activity of the 6 wt.% AgInS 2 /Er‐g‐C 3 N 4 heterocomposite in real wastewater highlights its potential as a promising and scalable material for practical environmental remediation applications.

Water pollution due to organic pollutants poses a significant environmental threat, necessitating the development of effective materials for their complete removal. This study introduces a novel Z-scheme ZnFe2O4/ MWCNT/BiOBr (ZMB) ternary composite to enhance the removal of brilliant green (BG) dye and tetracycline hydrochloride (TCH) antibiotic. The synthesized materials were comprehensively analyzed using a range of characterization techniques, including XRD, UV-Vis DRS, FTIR, SEM, TEM, EDX mapping, BET, and XPS. A series of ternary composite materials with varying percent mass ratios of ZnFe2O4 was synthesized, of which the optimized 6ZMB composite (6 % mass ratio of ZnFe2O4) demonstrates the highest degradation rates for BG (99.9 %) and TCH (95.1 %) within 20 and 100 min, respectively. Trapping experiments confirmed that O2 center dot- and center dot OH were the main reactive species responsible for the degradation of BG and TCH pollutants. The NBT transformation experiments and PL terephthalic acid probe method further confirmed the involvement of O2 center dot- and center dot OH, respectively. Furthermore, the adsorption isotherm study showed that BG adsorption onto the 6ZMB ternary composite predominantly followed the Langmuir model, with a high regression coefficient (0.9963 and 0.9777 for linear and nonlinear fit, respectively), indicating effective and consistent adsorption through chemisorption.

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A facile solvent-free solid-state method was adapted to synthesize the spherical-shaped Bi2WO6 engraved on phenyl-doped g-C3N4 nanosheet, i.e., Bi2WO6/Ph-gC3N4 (or BPCN) composites with varying weights of Bi2WO6. Several spectral analyses were used to characterize all the synthesized nanomaterials. The synthesized photocatalyst showed good absorption under visible light as confirmed by UV–visible DRS analysis. Morphological analyses like SEM and TEM determine the successful fabrication of binary heterocomposite. Further, the elements available in the fabricated binary nanocomposite were confirmed by XPS. The photocatalyst was used for the aerobic photocatalytic degradation of a few colorless pollutants like bisphenol A (BPA, 30 mg L−1), a microplastic constituent, and tetracycline (TC, 40 mg L−1), an antibiotic derivative to achieve the impressive results. The less intense PL signal obtained for the 20BPCN heterocomposite reveals the remarkable enhancement in e−-h+ pair separation and recombination rate. The quenching study, alkaline terephthalic acid photoluminescence test (TA-PL), and NBT phototransformation study explain the formation of reactive species involved in the decomposition process. An oral cancer cell line (A-254) was tested for the anticancer activity analysis of the 20BPCN photocatalyst. Based on the obtained results, a Z-scheme electron transfer mechanism has been proposed for the photodegradation of model compounds.

Photocatalysis is a flexible method of transforming solar energy into chemical energy. It has great potential for detoxification of wastewater and hydrogen production through water splitting. This study presents the synthesis of a Z-scheme-designed LaNiO3/g-C3N4/MWCNT (LGM) nanohybrid using a simple hydrothermal approach. Standard analytical techniques were employed to conduct a thorough characterization of the designed materials. The developed nanohybrid is designed to enhance the electron-hole pairs separation and conveyance of charge carriers through multiwall carbon nanotubes (MWCNT). A series of nanohybrids have been synthesized, which showed a remarkable photocatalytic degradation for methyl orange (MO, 90%) and bisphenol A (BPA, 95%). The maximum degradation was recorded using 20 wt% LaNiO3/g-C3N4/MWCNT (20LGM) nanohybrid. Furthermore, the synergistic production of hydrogen was found to be 19.62 mmolg−1cat over 10 wt% LaNiO3/g-C3N4/MWCNT (10LGM) nanohybrid under visible light irradiation. The photocatalytic efficiency remains nearly unchanged after four cycles representing the photochemical stability of the nanohybrids. The outcomes of the trapping study showed that superoxide radical anions (O2•-) and hydroxyl radicals (•OH) are actively involved in the degradation of the organic compounds. These results provide important information for photocatalytic environmental remediation and sustainable energy production as well.

Photocatalysis is a flexible method of transforming solar energy into chemical energy. It has great potential for detoxification of wastewater and hydrogen production through water splitting. This study presents the synthesis of a Z-scheme-designed LaNiO3/g-C3N4/MWCNT (LGM) nanohybrid using a simple hydrothermal approach. Standard analytical techniques were employed to conduct a thorough characterization of the designed materials. The developed nanohybrid is designed to enhance the electron-hole pairs separation and conveyance of charge carriers through multiwall carbon nanotubes (MWCNT). A series of nanohybrids have been synthesized, which showed a remarkable photocatalytic degradation for methyl orange (MO, 90%) and bisphenol A (BPA, 95%). The maximum degradation was recorded using 20 wt% LaNiO3/g-C3N4/MWCNT (20LGM) nanohybrid. Furthermore, the synergistic production of hydrogen was found to be 19.62 mmolg(cat)(-1) over 10 wt% LaNiO3/g-C3N4/MWCNT (10LGM) nanohybrid under visible light irradiation. The photocatalytic efficiency remains nearly unchanged after four degradation cycles representing the photochemical stability of the nanohybrids. The outcomes of the trapping study showed that superoxide radical anions (O-2(center dot-)) and hydroxyl radicals ((OH)-O-center dot) are actively involved in the degradation of organic compounds. These results provide important information for photocatalytic environmental remediation and sustainable energy production as well.

This study presents a ternary heterostructure comprising graphene oxide (GO) decorated BiOI/CdS, as a highly effective candidate for both the photodegradation and adsorption of organic pollutants. The composite materials were synthesized through a facile solvothermal method. The structural and morphological characteristics of the synthesized materials were thoroughly analyzed using various analytical techniques. Photoluminescence (PL) spectral analysis of the photocatalysts emphasises the strong charge-carrier separations in ternary composites, which is the main requirement for enhancing degradation performances. The photocatalysts were utilized to remove the methylene blue (MB) and doxycycline (DC) from aqueous suspensions. The most effective ternary composite (GO/BiOI/CdS-x, x = 0.4 mmol CdS) resulted in 99.2% degradation of MB within 25 min and 83.7 % degradation of DC within 150 min of light exposure. Trapping experiments identified O2 center dot- and h+ as the most active species in pollutant degradation. A Z-scheme mechanism, supported by Mott-Schottky plots, VB-XPS spectra, and active species observations, was proposed to elucidate degradation processes. Additionally, the GO/BiOI/CdS-0.4 ternary composite demonstrated impressive adsorption ability for MB, indicating its robust pollutant removal capability. The composite also demonstrated remarkable stability and an impressive ability to be reused, positioning it as a highly promising material for use in wastewater treatment.

The surge in industrial activities and a substantial increase in antibiotic usage, has led to the further deterioration of global water pollution problems. Focusing on this current scenario, we synthesize the g-C3N4-MWCNT/In2O3 (GMI) ternary composite to utilize for the photocatalytic degradation of levofloxacin (LF) antibiotic and crystal violet (CV) dye under visible light. The photocatalytic degradation of CV (15 mgL 1) and LF (40 mgL 1) was 99.7 % and 87.4 % respectively, in just 15 and 100 min of irradiation with GMI-0.2 nanocomposite. The removal rates of CV and LF with GMI-0.2 nanocomposite were 14.61 and 4.85 times more rapid than those observed with In2O3. Similarly, compared to g-C3N4, the removal rates for CV and LF were 7.34 and 3.98 times higher when using GMI-0.2 nanocomposite. The trapping experiments and ESR measurements indicated that O2 center dot was the predominant active species responsible for the photocatalytic degradation processes. In order to explain the degradation processes, a feasible photocatalytic mechanism for GMI ternary composite was proposed. The mechanism was based on the calculations of the band gaps and edge potentials of the synthesised materials as well as the findings of the quenching experiments. The GMI-0.2 nanocomposite was also used to treat human lung cancer cells, and it was discovered that cell viability with 100 mu g/mL of the photocatalyst was lowest in both dark (36 %) and in visible light (20 %).

Designing efficient catalysts with strong redox characteristics and high visible light absorption is of particular interest in the field of photocatalysis. In this study, we synthesized an active and cost-effective photocatalyst by combining MOF-derived La/Fe bimetallic LaFeO3 porous nanosheets with hydrothermally synthesized CdS nanorods. Several p-LaFeO3/n-CdS photocatalysts with different concentrations (wt%) of LaFeO3 were synthesized, and their physicochemical properties were characterized by standard analytical techniques such as UV-vis DRS, FTIR, XRD, BET, SEM, TEM, EDX and XPS. The photocatalytic degradation performance of the synthesized materials was evaluated using chromophoric dyes such as rhodamine B (RhB) and congo red (CR) and antibiotics such as tetracycline (TC) and oxytetracycline (OTC) under visible light irradiation in aqueous suspension. The as-synthesized 15 wt% p-LaFeO3/n-CdS (15 LC) heterojunction photocatalyst exhibited remarkable photocatalytic degradation performance against RhB (96%, 30 min), CR (98%, 25 min), TC (80%, 100 min), and OTC (78.6%, 75 min). The reactive oxygen species such as O-2(center dot)-, h(+), and (OH)-O-center dot were involved in the degradation process, which was monitored through scavenger tests. The heterojunction photocatalyst effectively suppressed photoinduced electron-hole pair recombination and facilitated interfacial charge transfer. Based on experimental data and projected energy band positions, a type II mechanism is proposed to elucidate the photocatalytic degradation of organic contaminants, emphasizing the redox capabilities and broad visible light absorption of the synthesized photocatalyst. The phototransformation of 4-nitrophenol to 4-aminophenol and adsorption isotherms were also done using the 15 LC heterojunction photocatalyst, whereas in the case of the adsorption isotherms the curve fitted the Langmuir isotherm model.

Improved photocatalytic performances can be achieved by synthesizing double heterojunction nanocomposites with suitable conduction band (CB) and valence band (VB) edge potentials. In the current study, a hydrothermal approach was used to successfully synthesize a Z-scheme CdS@g-C3N4/Bi2MoO6 (CdS@GB) ternary nano -composite with varied CdS contents. The photocatalytic efficiency of the as-synthesized materials was deter-mined by studying the degradation of Rhodamine B (RhB) and Acetaminophen (ACM) pollutants. The experimental results revealed that 15 wt% CdS@GB (15CdS@GB) ternary composite showed the highest pho-tocatalytic performance indicating 98.8 and 83% degradation of RhB and ACM in 35 and 140 min of irradiation, respectively. The stability of the ternary composite was also relatively high even after four consecutive cycles of photodegradation. The main reactive species involved in photodegradation processes was O2 & BULL;-as revealed by the quenching experiments. The nitro blue tetrazolium (NBT) experiment further confirmed it, which showed the high production of O2 & BULL;-in the reaction mixture. The synthesized ternary composites were used to study the dark adsorption of RhB, and the results confirmed the applicability of the Langmuir isotherm model. The electro-chemical properties of the synthesized materials were investigated using electrochemical impedance spectros-copy (EIS) and cyclovoltammetry (CV). The results showed that 15CdS@GB has the lowest charge-transfer resistance and highest specific capacitance. Based on the findings, a double Z-scheme mechanism route was designed and presented to explain the photodegradation of the target pollutants.

A ternary nanocomposite, In2O3/GO/BiVO4, was created using the hydrothermal process, establishing a heterojunction between In2O3 and BiVO4 with the addition of graphene oxide nanosheets. The synthesized materials underwent characterization using various standard analytical techniques, including diffuse reflectance spectroscopy (DRS), X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), electron spin resonance spectroscopy (ESR), energydispersive X-ray (EDX), and transmission electron microscopy (TEM). The developed materials showed notable efficacy in degrading MB dye and antibiotics such as ciprofloxacin and tetracycline, when exposed to visible light in an aqueous suspension. The photocatalyst, 10 wt% In2O3/GO/BiVO4 (10IBG) showed better activity compared with the pure and other composite materials. The enhanced activity could be attributed to the synergistic effects of charge carrier separation and electron mediation facilitated by graphene oxide via Z-scheme pathway. The successful integration of graphene oxide in the heterostructure underscores its potential as a promising strategy for developing high-performance photocatalysts for the elimination of organic pollutants. Furthermore, the mechanism investigation underlying photocatalytic degradation of organic pollutants using the 10IBG heterostructure photocatalyst is conducted through trapping experiments, which indicates that the degradation is primarily contributedby superoxide radical anions (O2 center dot-) and hydroxyl radicals (center dot OH). Moreover, 10IBG photocatalyst displayed remarkable anticancer activity against A549 lung cancer cell lines, whereas the cell viability was reduced from 18% in the dark medium to 58% when exposed to visible light. In terms of toxicity assessment, the 10IBG heterostructure photocatalyst demonstrated quick eradication of antibiotic toxicity and established itself as a promising and cost-effective photocatalyst for wastewater treatment.

Photocatalysis is realized by the design of a visible-light-active catalyst with robust redox capacity and broad absorption. In this study, a series of novel Z-scheme CoNiWO4/Ph-gC3N4 photocatalysts are synthesized to improve their redox property and photocatalytic activity toward broad visible light absorption. An intimate stable heterojunction is made between cobalt–nickel tungstate (CoNiWO4) and phenyl-doped graphitic carbon nitride (Ph-gC3N4), and its physicochemical properties are studied. The bifunctional properties of all of the synthesized materials were assessed by studying the decomposition of bisphenol A (BPA) and methyl orange (MO) dye as model pollutants, followed by an evaluation of their anticancer activity on human lung cancer cell lines. The photocatalyst with 20 wt % CoNiWO4 heterocomposite showed an enhanced response toward the removal of cancerous cells. The synthesized pristine CoNiWO4 and Ph-gC3N4 exhibit well-matched band structures and, hence, make it easier to create a Z-scheme heterocomposite. This may increase the lifetime of photoinduced charge carriers with a high redox power, thereby improving their photocatalytic and anticancer activity. An extensive analysis of the mechanism demonstrates that hydroxyl radicals (•OH) and superoxide radical anions (•O2–) are responsible for the degradation of organic compounds via Z-scheme charge transfer approach. These findings point toward a new route for creating effective Co–Ni tungstate-based direct Z-scheme photocatalysts for various redox processes, particularly the mineralization of resistant organic molecules.

In this study, an effective type-II heterojunction CdS/AgI binary composite was constructed by an in situ precipitation approach. To validate the successful formation of heterojunction between AgI and CdS photocatalysts, the synthesized binary composites were characterized by various analytical techniques. UV-vis diffuse-reflectance spectroscopy (UV-vis DRS) revealed that heterojunction formation led to a red shift in the absorbance spectra of the CdS/AgI binary composite. The optimized 20AgI/CdS binary composite showed a least intense photoluminescence (PL) peak indicating highly improved charge carrier (e-/h+ pairs) separation efficiency. The photocatalytic efficiency of the synthesized materials was assessed based on the degradation of methyl orange (MO) and tetracycline hydrochloride (TCH) in the presence of visible light. Compared to bare photocatalysts and other binary composites, the 20AgI/CdS binary composite showed the highest photocatalytic degradation performances. Additionally, the trapping studies showed that superoxide radical anion (O2•-) was the most dominant active species involved in photodegradation processes. Based on the results of active species trapping studies, a mechanism was proposed to describe the formation of type-II heterojunctions for CdS/AgI binary composite. Overall, the synthesized binary composite has tremendous promise for environmental remediation due to its straightforward synthesis approach and excellent photocatalytic efficacy.