Solvent-free Strategy Research Articles

Solvent-Free Synthesis of Bioactive Heterocycles

: The main emphasis of green chemistry is to reduce environmental pollution. Its main goal is to adopt a cost-effective and harmless strategy for human health and the environment. The green synthetic routes have succeeded in adopting solvent-free conditions as an effective tool for sustainability. Heterocycles are organic compounds that are widely distributed by nature. Many of them possess medicinal and pharmacological properties, as this heterocyclic moiety is found in many drugs. The solvent-free strategies for the Synthesis of bioactive heterocycles are, now-adays, regarded as an important objective. Solvent-free reactions are eco-friendly, cost-effective, and an environmentally benign route in organic transformation methods because of their effi-ciency, reduced reaction time, and high yields, thereby saving energy. This mini-review focuses on the environmentally benign solvent-free Synthesis of heterocycles and their potential pharma-cological applications.

Elucidating charge transfer process and enhancing electrochemical performance of laser-induced graphene via surface engineering with sustainable hydrogel membranes: An electrochemist's perspective

Laser-induced graphene (LIG) has emerged as a promising solvent-free strategy for producing highly porous, 3D graphene structures, particularly for electrochemical applications. However, the unique character of LIG and hydrogel membrane (HM) coated LIG requires accounting for the specific conditions of its charge transfer process. This study investigates electron transfer kinetics and the electroactive surface area of LIG electrodes, finding efficient kinetics for the [Fe(CN)6]3-/4- redox process, with a high rate constant of 4.89 x 10−3 cm/s. The impact of polysaccharide HM coatings (cationic chitosan, neutral agarose and anionic sodium alginate) on LIG's charge transfer behavior is elucidated, considering factors like ohmic drop across porous LIG and Coulombic interactions/permeability affecting diffusion coefficient (D), estimated from amperometry.It was found that D of redox species is lower for HM-coated LIGs, and is the lowest for chitosan HM. Chitosan coating results in increased capacitive share in the total current while does not apparently reduce Faradaic current. Experimental findings are supported by ab-initio calculations showing an electrostatic potential map's negative charge distribution upon chitosan chain protonation, having an effect in over a two-fold redox current increase upon switching the pH from 7.48 to 1.73. This feature is absent for other studied HMs. It was also revealed that the chitosan's band gap was reduced to 3.07 eV upon acetylation, due to the introduction of a new LUMO state. This study summarizes the operating conditions enhanced by HM presence, impacting redox process kinetics and presenting unique challenges for prospective LIG/HM systems' electrochemical applications.

One-Step Solvent-Free Strategy to Efficiently Synthesize High-Substitution Cellulose Esters

One-Step Solvent-Free Strategy to Efficiently Synthesize High-Substitution Cellulose Esters

Rapid Synthesis of Boron-MWW Zeolite Through a Solvent-free Strategy

Rapid Synthesis of Boron-MWW Zeolite Through a Solvent-free Strategy

Nanosized curing catalyst via nano-templated plasma PVD for attaining superior low-cure powder coating films

The addition of curing catalysts into powder coating is a key method to fabricate low-temperature curing powder coating for reducing energy consumption and expanding its applications to heat-sensitive substrates. However, the heterogeneous dispersion of the unmodified catalysts in powder coatings results in inconsistent catalysis of resin crosslinking, thus leading to compromised surface smoothness and gloss. Utilizing nanosized catalysts is an efficient solution to such problems. In this paper, we propose a nano-templated dielectric barrier discharge (DBD) plasma-assisted physical vapor deposition (PVD) strategy to fabricate the nanosized catalysts. The curing catalyst, 2-ethylimidazole (2-elm), is successfully vaporized and deposited on nano-carrier SiO2 (SiO2-NPs) in the DBD plasma reactor at atmospheric pressure, producing 2-elm@SiO2-NPs. The mechanical strength and chemical resistance of finishes of powder coating incorporated with the 2-elm@SiO2-NPs remained at low curing temperature (170 °C for 15 min) and fast curing condition (190 °C for 8 min). In addition, their surface qualities are comparable to that of the original powder coating, with up to 100 % gloss retention, successfully eliminating the issue of more than 25 % gloss attenuation of the powder coating with unmodified 2-elm. This study provides an effective, solvent-free strategy for fabricating nanosized curing catalysts and achieving high-quality film finishes.

Solvent-free strategy for facile synthesis and cytotoxicity evaluation of benzimidazole derivatives

This study reports a facile synthesis and the cytotoxic evaluation of N–H benzimidazoles. This synthetic method made use of the condensation reaction between o-phenylenediamine and benzylamine and was highlighted by its solvent-free reaction conditions and short reaction time with the use of Na2S2O5 as an inexpensive and environmentally friendly oxidizing agent. The cytotoxicity assays revealed that the benzimidazole derivatives 3l, 3h, and 3r displayed strong activity against the HeLa cancer cell line with the IC50 of 1.54 μM, 0.86 μM, and 1.03 μM, respectively, which were 5.6-fold, 10-fold, and 8-fold stronger than the positive control 5-fluorouracil (5-FU, IC50 = 8.61 μM). Furthermore, both compounds 3h and 3r exhibited similar cytotoxicities against MCF-7, which were equivalent to that of 5-FU and about 2.5-fold stronger than 5-FU towards the A549 cell line.

Heterointerface regulation of covalent organic framework-anchored graphene via a solvent-free strategy for high-performance supercapacitor and hybrid capacitive deionization electrodes.

Covalent organic frameworks (COFs) with customizable geometry and redox centers are an ideal candidate for supercapacitors and hybrid capacitive deionization (HCDI). However, their poor intrinsic conductivity and micropore-dominated pore structures severely impair their electrochemical performance, and the synthesis process using organic solvents brings serious environmental and cost issues. Herein, a 2D redox-active pyrazine-based COF (BAHC-COF) was anchored on the surface of graphene in a solvent-free strategy for heterointerface regulation. The as-prepared BAHC-COF/graphene (BAHCGO) nanohybrid materials possess high-speed charge transport offered by the graphene carrier and accelerated electrolyte ion migration within the BAHC-COF, allowing ions to effectively occupy ion storage sites inside BAHC. As a result, the BAHCGO//activated carbon asymmetric supercapacitor achieves a high energy output of 61.2 W h kg-1 and a satisfactory long-term cycling life. More importantly, BAHCGO-based HCDI possesses a high salt adsorption capacity (SAC) of 67.5 mg g-1 and excellent long-term desalination/regeneration stability. This work accelerates the application of COF-based materials in the fields of energy storage and water treatment.

Hot-Pressing Metal Covalent Organic Frameworks as Personal Protection Films.

Effective personal protection is crucial for controlling infectious disease spread. However, commonly used personal protective materials such as disposable masks lack antibacterial/antiviral function and may lead to cross infection. Herein, a polyethylene glycol-assisted solvent-free strategy is proposed to rapidly synthesize a series of the donor-acceptor metal-covalent organic frameworks (MCOFs) (i.e., GZHMU-2, JNM-1, and JNM-2) under air atmosphere and henceforth extend it via in situ hot-pressing process to prepare MCOFs based films with photocatalytic disinfect ability. Best of them, the newly designed GZHMU-2 has a wide absorption spectrum (200 to 1500nm) and can efficiently produce reactive oxygen species under sunlight irradiation, achieving excellent photocatalytic disinfection performance. After in situ hot-pressing as a film material, the obtained GZHMU-2/NMF can effectively kill E. coli (99.99%), S. aureus (99%), and H1N1 (92.5%), meanwhile possessing good reusability. Noteworthy, the long-term use of a GZHMU-2/NWF-based mask has verified no damage to the living body by measuring the expression of mouse blood routine, lung tissue, and inflammatory factors at the in-vivo level.

2D heterostructural Mn2O3 quantum dots embedded N-doped carbon nanosheets with strongly stable interface enabling high-performance sodium-ion hybrid capacitors

The ingenious architectural structural engineering is extensively identified as a cogent means for facilitating the electrochemical properties of conversion-type anode materials for sodium-ion storage. Herein, a delicate, scalable and controllable solvent-free strategy is proposed to synthesize ultrafine Mn2O3 quantum dots embedded into N-doped carbon to generate two-dimensional (2D) composites (MNC) with robust interfacial heterostructural interactions for high sodium ion storage and fast reaction kinetics, which averts the use of solvents and environmental pollution, greatly reduces time and production costs. The introduction of metallic Mn species simultaneously achieves the construction of ultrafine Mn2O3 quantum dots and strong interfacial heterostructural COMn bonds between metal species and 2D N-doped carbon matrix. The synergistic effect of the formation of oxide quantum dots, the combination of 2D N-doped carbon and the construction of robust interfacial interactions provides the stable electrode structure, fast reaction kinetics and high electrochemical storage capability of anode materials. Hence, MNC composites in SIBs convey remarkable reversible rate capability. Its superior capacity reaches 215 mAh g−1 for 50 cycles at 0.2 A g−1 and 155 mAh g−1 for 1000 cycles at a high current density of 5 A g−1, which shows good long-term stability. The assembled sodium-ion hybrid capacitors (SIHCs) device delivers outstanding energy density of 138 Wh kg−1 at a power density of 126 W kg−1 and 98% capacity retention after 2000 cycles at 2 A g−1, and tremendous capability for practical applications (69 LEDs can be easily lighted). This work not merely offers guidance for the rational interfacial engineering design of high-capacity Mn-based electrode materials in a feasible and scalable solvent-free tactics for Na+ storage, but also broadens the routes for projecting a better electrode material for other battery systems.

High-temperature shock enabled synthesis of ultrafine Ru nanoparticles anchoring onto tungsten carbide with strong metal-support interaction for ampere-level current density hydrogen evolution

Developing cost effective, active and durable alternatives to platinum electrocatalysts is the major challenge for sustainable hydrogen production. Rational design and controlled synthesis of hybrid structures with strong metal-support interaction may offer a feasible strategy to achieve efficient and stable hydrogen evolution reaction (HER). Herein, a low cost and high-performance ultrafine Ru nanoparticles anchored tungsten carbide (Ru/WC) HER electrocatalyst is successfully prepared by high-temperature shock (HTS) technology, which can be accomplished in less than 0.5 s. In a strong alkaline medium, the as-prepared Ru/WC exhibits a low overpotential of 4 mV and 72 mV at the current densities of 10 mA cm−2 and 100 mA cm−2, respectively. Low Tafel slope of 44 mV dec−1, high turnover frequency (TOF) of 2.55 s−1 at an overpotential of 100 mV, long-term electrochemical stability up to 150 h, and ampere-level current density can be achieved. Furthermore, Ru/WC also shows exceptional activity and stability under acidic conditions. Notably, Ru/WC can accommodate HER current density as high as 2000 mA cm−2 at a small overpotential of 365 mV, which holds great promises for industrial large-scale production. This work provides a simple, rapid, and solvent-free strategy for synthesizing high efficiency HER electrocatalyst with ampere-level current density.

Study on the Synthesis of Pine Sterol Esters in Solvent-free Systems Catalyzed by Candida rugosa Lipase Immobilized on Hydrophobic Macroporous Resin.

Pine sterol ester is a kind of novel food source nutrient with great advantages in lowering blood cholesterol levels, inhibiting tumors, preventing prostate enlargement, and regulating immunity. Macroporous resins with large specific surface area, stable structures, and various functional groups (epoxy, amino, and octadecyl groups) have been selected for immobilization of Candida rugosa lipase (CRL) to improve its stability and efficiency in the synthesis of pine sterol esters. A solvent-free strategy using oleic acid (substrate) as an esterification reaction medium is an important alternative for avoiding the use of organic solvents. The immobilization conditions of CRL immobilized on several kinds of commercial macroporous resins were optimized. Fortunately, by adsorption (hydrophobic interaction), a high immobilization efficiency of CRL was obtained using macroporous resins with hydrophobic octadecyl groups with an immobilization efficiency of 86.5%, enzyme loading of 138.5 mg/g and enzyme activity of 34.7 U/g. The results showed that a 95.1% yield could be obtained with a molar ratio of oleic acid to pine sterol of 5:1, an enzyme amount of 6.0 U/g (relative to pine sterol mass) at 50°C for 48 hours. The hydrophobic macroporous resin (ECR8806M) with a large specific surface area and abundant functional groups was used to achieve efficient immobilization of CRL. CRL@ECR8806M is an efficient catalyst for the synthesis of phytosterol esters and has the potential for further large-scale applications. Therefore, this simple, green, and low-cost strategy for lipase immobilization provides new possibilities for the high-efficiency production of pine sterol esters and other food source nutrients. This article is protected by copyright. All rights reserved.

Achieving a novel solvent-free regeneration of LiBH4 combining hydrogen storage and production in a closed material cycle

LiBH 4 has been considered as one of the most promising energy storage materials with its ultrahigh hydrogen capacity, which can supply hydrogen through hydrolysis process or realize hydrogen-to-electricity conversion via anodic oxidation reaction of direct borohydride fuel cells (DBFCs). However, the realization of practical hydrogen applications heavily depends on the effective synthesis of high-purity LiBH 4 and recycling of the spent fuels (LiBO 2 ·xH 2 O). The present work demonstrates a convenient and high-efficiency solvent-free strategy for regenerating LiBH 4 with a maximum yield close to 80%, by retrieving its by-products with MgH 2 as a reducing agent under ambient conditions. Besides, the hydrogen released from the regeneration course can completely compensate the demand for consumed MgH 2 . The isotopic tracer method reveals that the hydrogen stored in LiBH 4 comes from both MgH 2 and coordinated water bound to LiBO 2 . Here, the expensive MgH 2 can be substituted with the readily available and cost-effective MgH 2 −Mg mixtures to simplify the regeneration route. Notably, LiBH 4 catalyzed by CoCl 2 can stably supply hydrogen to proton exchange membrane fuel cell (PEMFC), thus powering a portable prototype vehicle. By combining hydrogen storage, production and utilization in a closed cycle, this work offers new insights into deploying boron-based hydrides for energy applications.

Constructing an efficient electrocatalyst for water oxidation: an Fe-doped CoO/Co catalyst enabled by in situ MOF growth and a solvent-free strategy.

The development of non-precious metal electrocatalysts with high activity for the oxygen evolution reaction (OER) is a crucial and challenging task. In this work, we proposed a solvent-free in situ metal-organic framework (MOF) growth strategy for the fabrication of an Fe-doped CoO/Co electrocatalyst. This approach not only partially granted the MOF's porous structure to the catalyst but also resulted in a tighter combination between the Co metal and CoO, thereby enhancing its electrical conductivity. Furthermore, this method enabled the Fe species to be more uniformly dispersed on CoO/Co, which significantly exposed more active sites for efficient electrocatalysis. The entire synthesis process was solvent-free, except for a small amount of water and ethanol used during catalyst washing. The as-synthesized Fe-CoO/Co electrocatalyst exhibited superior OER activity on a glass carbon electrode, with η = 276 mV at a current density of 10 mA cm-2, even higher than that of the commercial precious IrO2/C catalyst. Additionally, it was also extended to prepare a Ni-doped CoO/Co electrocatalyst by the same procedure with satisfactory OER performance. This work presents a new preparation approach for MOF-derived catalysts with potential applications in energy conversion and beyond.

A solid-state synthetic strategy toward nickel-based bimetallic interstitial compounds (MNi3Cx, M = Zn, In, Ga).

Bimetallic interstitial compounds with unique geometric properties have attracted increasing attention in energy-related fields and diverse chemical transformations. Current synthesis of these compounds generally involves at least one wet-chemistry step with the use of various solvents to prepare the bimetallic precursors, and no universal protocols for different compositions are yet available. Herein, a novel synthetic strategy toward a platform of nickel-based bimetallic interstitial compounds with the formula MNi3Cx, M = Zn, In, and Ga, was developed based on a straightforward solid-state transformation, i.e., simply annealing the hydroxides of the respective metals in the presence of different carbon precursors (cyanamide, dicyandiamide, melamine, and urea) in a hydrogen stream. The key process parameters influencing the compositions of the final products are studied and the formation mechanism is discussed based on advanced characterization techniques. Powder X-ray diffraction reveals MNi3Cx as a single phase and electron microscopy shows that the MNi3Cx particles are covered with N-doped carbon shells. Extrapolation to other bimetallic interstitial compounds failed when following the above protocol, and the successful examples are linked to the formation of the corresponding bimetallic alloys in the absence of carbon precursors. When evaluated for the selective hydrogenation of dimethyl oxalate, both InNi3C0.5 and ZnNi3C0.7 show comparable high activity. While ZnNi3C0.7 delivers the highest selectivity for methyl glycolate, tunable methyl glycolate and ethylene glycol are formed on InNi3C0.5. In general, this facile solvent-free strategy affords an interesting scaffold to fabricate more advanced multi-metallic interstitial compounds with broad applications.

Intelligent colorimetric soy protein isolate-based films incorporated with curcumin through an organic solvent-free pH-driven method: Properties, molecular interactions, and application

The preparation of intelligent colorimetric films based on soy protein isolate and curcumin at different final pHs was investigated by using blending and pH-driven methods with curcumin-free films as blank controls. It was found that the films loaded with curcumin using the pH-driven method exhibited enhanced ductility and water resistance with an elongation at break of 122 ± 6% and water vapor permeability of 1.70 ± 0.01 × 10 −10 g·m/m 2 ·Pa·s. The Fourier transform infrared (FTIR) spectroscopy results showed that curcumin was loaded in the film network mainly through hydrogen bonds and hydrophobic interactions. The curcumin encapsulated using the pH-driven method was present in an amorphous form, which effectively suppressed the adverse effect of curcumin blending on film opacity and increased the UV blocking ability of the films. The high encapsulation efficiency and reduced thermal degradation of curcumin resulted in enhanced antioxidant activity of the films with high 2,2-diphenyl-1-picrylhydrazyl (DPPH) and 2,2′-azinobis (3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) radical scavenging activities of 102.91 ± 0.83 Trolox equivalent (TE)/g and 211.47 ± 5.20 μg TE/g, respectively. Furthermore, films showed better color responsiveness to volatile amines than curcumin-blended films. In particular, the films generated with a film-forming solution at pH 8 had the strongest color sensitivity in the presence of low concentrations of volatile amines. In shrimp storage experiments, only the films prepared using the pH-driven method identified the freshness of the shrimp based on visual observation. Hence, the pH-driven method might represent a promising organic solvent-free method for the preparation of intelligent packaging films. • An organic solvent-free strategy was proposed to prepare curcumin-loaded films. • Amorphous curcumin was loaded by hydrogen bonds and hydrophobic interactions. • The films had good antioxidant activity and color response to volatile amines. • The films were suitable for real-time freshness monitoring of shrimp.

Ionothermal Synthesis of Fully Conjugated Covalent Organic Frameworks for High-Capacity and Ultrastable Potassium-Ion Batteries.

Fully aromatic conjugated covalent organic frameworks (FAC-COFs) with excellent physicochemical stability have been emerging as active semiconductors for diverse potential applications. Developing efficient synthesis methods for fabricating FAC-COFs will significantly facilitate the exploration over their material and photonic/electronic functionalities. Herein, a facile solvent-free strategy is developed for the synthesis of 2D phthalocyanine-based FAC-COFs (FAC-Pc-COFs). Cyclopolymerization of benzo[1,2-b:4,5-b']bis[1,4]benzodioxin-2,3,9,10-tetracarbonitrile (BBTC) and quinoxalino[2',3':9,10]phenanthro[4,5-abc]phenazine-6,7,15,16-tetracarbonitrile (QPPTC) in ZnCl2 leads to the fast formation and isolation of BB-FAC-Pc-COF and QPP-FAC-Pc-COF, respectively. Powder X-ray diffraction and electron microscopy analysis reveal their crystalline nature with sql topology and AA stacking configuration. Thermogravimetric analysis and immersion experiment indicate their excellent stability. The conductivity test demonstrates their high conductivity of 0.93-1.94×10-4 Scm-1 owing to the fully π-conjugated electronic structural nature. In particular, the as-prepared FAC-Pc-COFs show high-performance K+ storage in potassium-ion batteries due to their excellent conductivity, highly ordered and robust structure, and N/O-rich framework nature. Impressively, QPP-FAC-Pc-COF shows a large reversible capacity of 424mAhg-1 after 100cycles at 50mAg-1 and a capacity retention of nearly 100% at 2000mAg-1 for over 10000cycles.

A Simple Solvent-Free Strategy of Polybenzoxazine Film Elaboration with Controllable Performance via Molecular Weight Regulation between Cross-Linking Knots

A Simple Solvent-Free Strategy of Polybenzoxazine Film Elaboration with Controllable Performance via Molecular Weight Regulation between Cross-Linking Knots

Highly efficient removal of organic contaminants and hydroxylamine hydrochloride enhancement effect based on magnetic iron/nitrogen doped carbon nanolayer

Developing highly effective and environmental friendliness Fe-based catalysts have attracted increasing attention. Herein, novel nitrogen-doped carbon nanolayer with Fe0/Fe3C nano-particles (Fe@NCL-900) were innovatively fabricated by a simple solvent-free strategy, pyrolyzed the mixture of 4,6-dihydroxypyrimidine and ferric chloride hexahydrate under 900 ℃. In the presence of peroxymonosulface (PMS), Fe@NCL-900 could remove almost 100% Carbamazepine in 6 min with an amazing apparent first-order constant (kobs) as high as 0.733 min−1, about 72 and even 88 times higher than that of the commercial zero-valent iron and the traditional Fenton system, respectively, which was mainly ascribed to the synergistic effect of high graphite carbon and excellent reducing ability of Fe0. Moreover, high valent iron species (Fe (IV)) and four types of reactive oxygen species (ROS) including hydroxyl radical (•OH), sulfate radical (SO4•-), singlet oxygen (1O2), superoxide radical (O2•-) were detected to play a key role in Carbamazepine removal by electron paramagnetic resonance (EPR) and the radical quenching experiments. Interestingly, it was observed that the addition of hydroxylamine hydrochloride could effectively improve the production of more ROS and the first-order constant was enhanced by 7.6 times (5.593 min−1), completely different from the previous reports that hydroxylamine hydrochloride in high concentrations would inhibit the removal rate. Moreover, the magnetically separable catalyst possessed a wide pH range (2.0–10.0) and superior reusability. This study provides novel insights for manufacturing a promising Fe-based nitrogen-doped catalyst in practical wastewater treatment.

Visible light assisted heterojunction composite of AgI and CDs doped ZIF-8 metal-organic framework for photocatalytic degradation of organic dye

• CDs@ZIF-8@AgI was prepared by a solvent-free way coupled to ion deposition strategy. • Acridine Orange can be effectively degraded by CDs@ZIF-8@AgI under visible light. Water pollution induced by the productive process of organic dyes would lead to various diseases, and so treatment of the wastewater is an urgent task for protecting human health and ecological environment. In this work, visible light responsive heterojunction material based on silver iodide and carbon dots (CDs) doped ZIF-8 metal organic frameworks (CDs@ZIF-8@AgI) has been prepared by a green solvent-free strategy and in-situ ion deposition method. The CDs@ZIF-8@AgI composites have high photocatalytic performance for degradation of acridine orange (AO) dye under visible light, and the maximum degradation percentage can reach to 96.0%, which was estimated by the UV-visible spectroscopy. The porous structure and large surface area of the photocatalyst were favorable to absorption of the target dye on the catalyst, which can promote the kinetic degradation rate for low level concentration of the dye. The introduction of CDs into the AgI heterojunction can improve the electron transport efficiency and visible light absorption capacity, and thus significantly enhancing the photocatalytic activity of the catalyst. The photocatalytic mechanism was proposed as indirect Z-scheme heterojunction type based on the energy band structure of the catalyst. This work provides a visible light photocatalyst for removal of the AO dye in wastewater and offers a promising strategy for developing photocatalyst for treatment of organic pollutants in the environment using solar energy.

Synthesis and characterization of rGO supported silver doped bimetallic ZnCo2O4 spinel oxides for enhanced photocatalytic degradation of industrial effluents

In the current report, Silver doped Zinc Cobaltite (AgZnCo 2 O 4 , AgZCO) nanoparticles have been synthesized through a solvent-free strategy. Synthesized AgZCO nanoparticles were integrated with the reduced graphene oxide (rGO) sheets to prepare the AgZCO@rGO composite. Structural and morphological properties of ZCO, AgZCO, and AgZCO@rGO were studied by various physio-chemical techniques. X-rays diffraction (XRD) analysis showed that all prepared samples possess face-centered cubic crystal structures with crystallite sizes of 5.79 nm, 5.27 nm, and 5.16 nm for ZCO, AgZCO, and AgZCO@rGO, respectively. Scanning electron microscope (SEM) analysis displayed that small spherical nanoparticles of AgZCO were wrapped inside rGO, along with some of the particles present on the surface of rGO sheets. FT-IR characterization showed the presence of all necessary vibrational modes. The results of the photocatalytic experiment showed that 41.97%, 58.02%, and 75.30% MB dye was degraded by the ZCO, AgZCO, and AgZCO@rGO respectively. 65.06% methyl orange dye was degraded by the AgZCO@rGO and it showed the highest percentage degradation with a higher kinetic rate than ZCO and AgZCO catalysts. • Ag substituted ZnCo 2 O 4 was synthesized by auto-moisturization method. • AgZnCo 2 O 4 nanoparticles were fabricated with rGO sheets. • rGO@ AgZnCo 2 O 4 and AgZnCo 2 O 4 were employed for the degradation of MB dye. • rGO@ AgZnCo 2 O 4 showed superior photo-degradation of MB with 75.30% removal within 105 min