Hybrid Nanocatalyst Research Articles

Light-induced in-situ transformation from MOF to construct heterostructured Co3O4/Co catalyst for efficient photothermal catalytic oxidation

The construction of hybrid nanocatalysts with enhanced active surfaces/interfaces is crucial for the catalytic oxidative removal of volatile organic compounds (VOCs). In this study, we report an in-situ conversion approach to synthesize a heterostructured Co3O4/Co catalyst (Co@NC-0.5) for efficient photothermal catalytic oxidation of acetone. The catalysts were prepared by pyrolyzing a mixture of ZIF-67 and melamine. The exposed cobalt species underwent in-situ oxidation to form a Co3O4/Co heterostructure under photothermal conditions. This unique catalyst structure exhibited over 90 % conversion within 16 min under full solar spectrum irradiation and excellent reusability with continuous maintenance of 100 % acetone conversion rate after nine cycles performance tests. Notably, its specific mass activity under thermocatalytic conditions was 2.13 times higher than that of Co3O4. Our work provides a facile and effective strategy for developing highly active and durable non-precious metal catalysts suitable for various photothermal catalytic reactions.

High value-added fuel additive production from waste bio-glycerol over a versatile nanohybrid catalyst

This study presents a pioneering nanohybrid catalyst featuring hierarchically porous dual-functional (acid–base) active sites, which is a versatile catalyst for the crucial bio-glycerol acetalization reaction.

Synthesis and characterization of hybrid nanocatalyst (AgNPs-Fe2O3) for catalytic remediation of hazardous 2,4-dinitrophenol

Hybridized nanocatalysts (AgNPs-Fe2O3) were prepared with silver nitrate and ferric chloride in the presence of sodium borohydride. The synthesized nanocatalyst was calcined, milled, and sieved for further applications. The nanocatalyst was characterized using Fourier transform infrared spectroscopy (FTIR) for the identification of functional moieties involved in the synthesis of the nanocatalyst. The vibrations of Fe and Ag were found at 566, 790 and 892 cm-1. The crystalline nature of the nanocatalyst was determined using X-ray diffraction (XRD) studies. The diffraction peaks for Ag and Fe can be seen at 2θ values of 30.42, 44.36, 62.45, 42.24 and 53.25. The morphology and elemental analysis of nanocatalysts were studied using scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDAX). The particles are found to be spherical in shape. The signal for Ag and Fe can be found at 3.0 keV and 0.7, 6.3, 7.0 keV, respectively. The synthesized nanocatalyst was employed in the remediation of 2,4-dinitrophenol. The AgNPs-Fe2O3 nanocatalyst completely reduced (97%) the 2,4-dinitrophenol to 2,4-diaminophenol within 24 h.
 KEY WORDS: Nanocatalyst, Chemical precipitation, Impregnation methodology, Milling, Sieving, Remediation
 Bull. Chem. Soc. Ethiop. 2024, 38(1), 113-121. DOI: https://dx.doi.org/10.4314/bcse.v38i1.9

Innovative development of hybrid nanocatalyst (ATH-ZnONPs) through green methods for achieving visible light-induced photocatalytic aerobic oxidation of benzyl alcohols into corresponding aldehydes and ketones

In recent research, there has been a surging interest in green methods for manufacturing metal oxide photocatalysts and enabling organic transformations in gentle conditions. This study achieved a groundbreaking development, introducing zinc oxide nanoparticles sensitized with anthocyanin dye (ATH-ZnONPs) for the very first time. The reducing agents in pomegranate leaves were utilized to synthesize ZnONPs from zinc salt. Simultaneously, anthocyanin dye was extracted from pomegranate flowers and linked with the ZnONPs. The FT-IR functional group analysis provided evidence of the successful conjugation of ZnONPs and ATH dye. SEM, EDX, and Elemental Mapping analysis unveiled the spherical morphology and nanocrystalline structure of ATH-ZnONPs, with particle sizes falling within the range of 50–70 nm. XRD analysis verified the hexagonal structural configuration of ZnONPs within the hybrid nanocomposite, with calculated lattice parameters of a = 3.261 Å and c = 5.207 Å. UV–Vis and DRS spectroscopy demonstrated that the composite efficiently harnesses visible light irradiation, exhibiting an energy bandgap of 2.22 eV. The assessment of ZnONPs through BET analysis unveiled a pore volume of 0.053 cm3/g, an SSA of 14.223 m2/g, and an average pore size of 4.18 nm, underscoring the mesoporous characteristics of ZnONPs. Importantly, the photocatalytic performance of the synthesized ATH-ZnONPs was thoroughly examined under blue LED light exposure. This investigation encompassed the evaluation of catalyst dosage, the impact of the light source, stability, regeneration, and the potential for reuse in the aerobic oxidation of benzyl alcohols, resulting in their corresponding aldehydes and ketones. 1HNMR and 13CNMR were used to characterize the products. The results of these studies highlight the versatile potential of this composite for a wide range of photocatalytic applications.

Enhanced catalytic activity of PMo11V/NiO/PAN nanosphere composite for real fuel oxidation desulfurization: Synthesis and characterization

In this paper, the sol-gel technique was used to successfully synthesize a new nanocomposite PMo11V/NiO/PAN, which includes Polyaniline substitute polyoxometalate (PMo11V), as well as Nickel (NiO) and Polyaniline (PAN). A novel heterogeneous nanocatalyst, PMo11V/NiO/PAN, has been proposed as a productive solution for extensive Sulphur removal of real model fuel/gas oil. To characterize the synthesized nanocomposite, multiple using methods like FT-IR, SEM, XRD, UV–Vis and EDX were utilized. The techniques employed include ultraviolet–visible (UV–Vis), X-ray diffraction (XRD), and EDX. The PMo11V/NiO/PAN nanocomposite had particles that were 50–60 nm in size and were spherical in shape at the nanoscale. The goal of the experiment was to remove sulphur-containing compounds from gasoline and model fuel through oxidative desulfurization. The Oxidative desulfurization (ODS) method showed improved performance with the prepared PMo11V/NiO/PAN nanosphere nanocomposite. According to the ODS results, the ordinary gasoline sulphur concentration decreased by 97 % at 35 °C after just 1 h. The hybrid nanocatalyst PMo11V/NiO/PAN doesn't suffer a significant decrease in its catalytic activity even after being used five times. Experimental results indicate that PMo11V/NiO/PAN nanocomposite can serve as a highly promising inorganic-inorganic composite catalyst for ODS system.

Spatial separation strategy to construct N/S co-doped carbon nanobox embedded with asymmetrically coupled Fe-Co pair-site for boosted reversible oxygen electrocatalysis

The fabrication of a remarkably efficient iron-metal-based pair-site, constrained within carbon support, presents a significant and intricate undertaking, primarily attributable to the propensity of proximate metallic entities to amalgamate into the alloy state. In response to this challenge, a spatial segregation approach was conceptualized, aiming to synthesize an N/S co-doped carbon nanobox hosting an asymmetrically coupled Fe-Co pair-site. This engineered nanostructure manifested remarkable electrocatalytic properties, notably featuring a superb half-wave potential of 0.903 V for the oxygen reduction reaction (ORR) and a commendable overpotential of 0.296 V at 10 mA/cm2 for the oxygen evolution reaction (OER). Additionally, a homemade Zn-air battery incorporating this nanohybrid catalyst demonstrated a discharge capacity of 737 mAh/g, a specific maximum power density of 239 mW/cm2 as well as notable durability. Work-function calculations suggested that the electronic interaction between Fe and Co phases, along with the synergetic catalysis of N/S co-doped carbon substrate, could facilitate charge redistribution at the interface, create abundant active sites, and optimize the adsorption–desorption energy of oxygen species on the active center, thus markedly reducing the ORR/OER catalytic reaction barriers. These findings highlight a new strategy for designing and synthesizing efficient bifunctional carbon-based catalysts for energy storage and conversion devices.

Fabrication of Ru loaded MgB2 with guar gum hybrid for photocatalytic degradation of crystal violet

Today, dyes/pigment-based materials are confronting a serious issue in harming marine ecology. Annihilate these serious water pollutants using photoactive 2D nanohybrid catalysts showed promising comparativeness over available photocatalysts. In the present work, a facile route to decorate Ruthenium (Ru) on 2D MgB2 flower-like nanostructures was developed via ecofriendly guar gum biopolymer substantial template (MgB2/GG@Ru NFS) and its photocatalytic performance was reported. Synthesis of MgB2@Ru, MgB2/GG@Ru NFS and commercial MgB2, was studied by FTIR, XRD, FE-SEM, EDX, AFM, TEM, UV–vis spectra, and XPS analysis. From the results, the MgB2/GG@Ru NFS exhibited a superior photocatalytic performance (99.7 %) than its precursors MgB2@Ru (79.7 %), and MgB2 (53.7 %), with the degradation efficiency of the crystal violet (CV) within 100 min under visible light irradiation. The proposed photo-catalyst MgB2/GG@Ru NFS showed negligible loss of photocatalytic activity even after five successive cycles, revealing its reusability and enhanced stability due to the network structure. The photocatalytic mechanism for MgB2/GG@Ru NFS was evaluated by trapping experiment of active species, verifying that superoxide (O2−) and electron (e−) contributed significant role in the dye degradation.

2D g-C3N4 nanosheets functionalized with nickel-doped ZrO2 nanoparticles for synergistic photodegradation of toxic chemical pollutants

The photocatalytic removal of toxic chemical pollutants from wastewater has garnered significant attention in recent times owing to its notable removal efficiency, cost-effectiveness, and eco-friendly characteristics. Nonetheless, this catalytic process necessitates augmented charge separation and distinctive interface properties to facilitate catalytic reactions for water treatment applications. Therefore, in the current study, novel g-C3N4/Ni-doped ZrO2 heterostructured hybrid catalysts have been synthesized via a hydrothermal approach. Microscopic studies reveal that ZrO2 nanospheres were distributed on the layered-like 2D structure of g-C3N4 nanosheets. Electrochemical impedance spectroscopy (EIS), X-ray photoelectron spectroscopy (XPS), UV–Vis diffuse reflectance spectroscopy (UV-DRS), and photoluminescence (PL) characterizations were employed to investigate the impact of bandgap, electron-hole recombination, charge transfer, and interface properties on the catalytic performance of g-C3N4/ZrO2 hybrids. XRD analysis confirmed that the Ni-ions do not disturb the host lattice crystal structure and heterostructure development between g-C3N4 and doped ZrO2 sample. Structurally, Ni-doped nanoparticles were found to be equally superficially dispersed on g-C3N4 sheets. Optical analysis results suggest that the hybrid catalyst possesses a narrow bandgap of 2.56 eV. The synthesized photocatalyst degraded rhodamine B (RhB) and tetracycline (TC) with ∼92% and ∼89% degradation efficiency, respectively. Heterostructured hybrid catalysts showed superior degradation rate constants than other catalysts. This might be attributed to the sufficient separation of electron-hole due to the development of a heterojunction. The radical scavenging experiments suggested that O2●- and ●OH radicals contributed substantially to the dye elimination activity of the composite. Therefore, the synthesized novel nanohybrid catalysts in this study present an efficient and straightforward synthesis method for the efficient removal of toxins from wastewater under visible light irradiation.

A novel CoMoO4 enwrapped ZIF-8 nanocomposite with enhanced visible light photocatalytic activity

A hybrid nano catalyst, CoMoO4 anchored zeolitic imidazolate framework-8 (ZIF-8) has been synthesized by simplest in-situ chemical method. The characterization results showed that the CoMoO4@ZIF-8 composites had a crystalline structure with a uniform distribution of the Cobalt molybdate particles on the ZIF-8 surface. The FTIR spectra revealed the presence of characteristic peaks for both ZIF-8 and CoMoO4, indicating the successful incorporation of the metal molybdate into the ZIF-8 framework. The SEM-EDS analysis showed that the CoMoO4 nanoparticles (NPs) have been evenly distributed on the ZIF-8 surface. In HRTEM, some rod-like CoMoO4 is observed on the surface of the ZIF-8 material, which is stacked in a disorderly manner and a porous channel structure is formed. The photocatalytic activity of the CoMoO4@ZIF-8 has been evaluated using the degradation of methylene blue (MB) and antibiotic Ciprofloxacin (CIP) under visible light. The optimal photocatalytic activity was achieved with the CoMoO4@ZIF-8 composite, which showed a degradation efficiency of 100% under visible light after 40 min of irradiation. In conclusion, the CoMoO4@ZIF-8 composites showed enhanced photocatalytic activity under visible light, and it exhibited the best performance compared with pure CoMoO4 and ZIF-8.

Regioselective direct thiocyanation of anilines and phenols using novel hybrid nanocatalyst (MgONPs@VCA) under visible light induced photoredox catalysis

Researchers have become increasingly interested in conjugating organic moieties with metal oxide nanoparticles due to their facile, diverse applications. This study introduces a novel nanocomposite material, magnesium oxide nanoparticles conjugated vitamin C adduct (MgONPs@VCA), created by combining magnesium oxide nanoparticles (MgONPs) and vitamin C adduct (VCA) to improve its optical properties and photocatalytic activity. The identity of the fabricated nanocatalyst was confirmed using a range of techniques, including Fourier-transform infrared (FT-IR) spectroscopy, X-ray diffraction (XRD), scanning electron microscopy (SEM), Elemental Mapping, energy dispersive spectroscopy (EDS) analysis, Photoluminescence (PL), and UV–vis differential reflectance spectroscopy (DRS). Later, under visible light irradiation (blue light), the photocatalytic performance of the nanocatalyst was evaluated as a photoredox catalyst for thiocyanation of various phenols and anilines under mild conditions, resulting in good to super conversion rates. In addition, the study thoroughly investigated the stability, regeneration, reusability, catalyst dosage, and light source effects. Mechanistic studies showed that the reaction followed a photoredox radical pathway.

A hierarchical strategy for fabricating synergistic 3D network bio-based porous carbon and 0D niobium-based bimetallic oxides as counter electrodes for I- and Cu-mediated dye-sensitized solar cells with N719 and Y123 dyes

Designing cost-effective counter electrode (CE) catalysts with advanced nanostructures and exploring their application in different dye-electrolyte systems is crucial for the development of dye-sensitized solar cells (DSSCs). In this work, two types of 3D network bio-based porous carbon (3D-BPC) loaded 0D niobium-based bimetallic oxide nanohybrids (CoNb2O6/3D-BPC and NiNb2O6/3D-BPC) were synthesized using a hierarchical strategy. Benefiting from the optimization of the electron transport pathways and enrichment of catalytically active sites via the hierarchical 0D/3D structure, formed by 3D-BPC and MNb2O6 (M = Co, Ni), the catalytic reduction ability of MNb2O6/3D-BPC was significantly enhanced. To explore the photovoltaic performance of the MNb2O6/3D-BPC based DSSC, the I3−/I− electrolyte and N719 dye system and the Cu2+/Cu+ electrolyte and Y123 dye system were simultaneously employed. The solar cells assembled with the CoNb2O6/3D-BPC and NiNb2O6/3D-BPC CE exhibited device efficiencies of 7.03% and 7.14% in the N719-I3−/I− system, respectively, and 1.84% and 2.42% in the Y123-Cu2+/Cu+ system, respectively, which were almost equal to those of Pt under the same system. Additionally, MNb2O6/3D-BPC catalysts exhibited promising stability in I3−/I− electrolyte. This work provides guidance for the construction of low-cost and high-efficiency nanohybrid catalysts for new energy conversion devices.

A New Neodymium Complex on Boehmite Nanoparticles with 1,3‐Bis(pyridine‐3‐ylmethyl)thiourea as a Practical and Reusable Nanocatalyst for the Chemoselective Synthesis of Tetrazoles

AbstractIn first part, boehmite nanoparticles were synthesized using aqueous solutions of NaOH and Al(NO3)3 ⋅ 9H2O. Then, it surface was modified by 3‐choloropropyltrimtoxysilane, and further 1,3‐bis(pyridin‐3‐ylmethyl)thiourea was anchored on the modified boehmite nanoparticles. In the final step, a neodymium complex was stabilized on its surface (Nd‐bis(PYT)@boehmite NPs). The obtained nanoparticles were characterized by TGA, BET, ICP, EDS, WDX, SEM, and XRD techniques. In the second part, Nd‐bis(PYT)@boehmite NPs were employed as an efficient, recoverable, and organic‐inorganic hybrid nanocatalyst in the homo‐selective synthesis of tetrazole compounds. The chemoselectivity of Nd‐bis(PYT)@boehmite NPs was studied in the [3+2] cycloaddition of phthalonitrile and sodium azide (NaN3). This catalyst is stable and has heterogeneous nature therefore it can be recovered and used again for several consecutively run without any re‐activation

A Novel Powerful γ-Fe2O3 @ CPTMS - Diethylene Triamine (DETA) @SO3H as a Heterogeneous Nanocatalyst, Recyclable and Efficient via Microwave-assisted for the Synthesis of Benzoxazinone- 4(3H)-one Derivatives in Green Media

Background: In order to synthesize benzoxazin-4 (3H) -one derivatives, a new inorganic- organic super-magnetic nano-hybrid (γ‐Fe2O3@ CPTMS-DETA @SO3H) nanocatalyst of the modified sulfuric acid represents a green and efficient catalyst to perform a three-component condensation reaction between various acyl chlorides, anthranilic acid and acetic anhydride (as cyclization agent), in one-pot and solvent-free conditions under microwave irradiation (4a-q). Introduction: In recent years, one of the most important subjects in synthetic organic chemistry has been green synthesis, which has applied environmentally friendly and efficient methods to synthesize biological derivatives. The use of catalysts has significant advantages, including simple separation and preparation, chemical and thermal stability, and eco-friendly nature and their features such as reusability, low cost, high efficiency and easy operation. Therefore, the mechanism is performed by a non-toxic organic catalyst that uses the chemical reactants and the least energy in accordance based on the least waste and green chemistry. Methods: Sequential addition and one-pot methods were applied to produce benzoxazinone derivatives. In the sequential addition approach, the reaction was begun by adding anthranilic acid and acetic anhydride to the reaction vessel under microwave irradiation and continued by adding γ‐ Fe2O3@ CPTMS-DETA @SO3H as super-magnetic nano-hybrid recyclable green catalysts and the desired acyl chlorides. Results: The main objective of this project was to synthesize benzoxazin-4 (3H) -one derivatives in the presence of super-paramagnetic organic-inorganic nanohybrid particles based on improved sulfonic acid (γ- Fe2O3 @ SiO2 - DETA @ SO3H) as an efficient recyclable heterogeneous catalyst. Conclusion: This paramagnetic nano-organocatalyst was characterized by EDX, VSM, TGA, FESEM, FT-IR, and XRD. Advantages of this catalyst include easy preparation, clear and easy operation, short reaction time (15–30 min), as well as without the use of toxic catalysts. In addition, the catalyst can be separated from the reaction solution using an external magnet by magnetic decantation; it can be recycled up to six times without reducing its activity.

Tuning the Electronic Properties of Platinum in Hybrid‐Nanoparticle Assemblies for use in Hydrogen Evolution Reaction

AbstractPlatinum is the best electrocatalyst for the hydrogen evolution reaction (HER). Here, we demonstrate that by contact electrification of Pt nanoparticle satellites on a gold or silver core, the Fermi level of Pt can be tuned. The electronic properties of Pt in such hybrid nanocatalysts were experimentally characterized by X‐ray photoelectron spectroscopy (XPS) and surface‐enhanced Raman scattering (SERS) with the probe molecule 2,6‐dimethyl phenyl isocyanide (2,6‐DMPI). Our experimental findings are corroborated by a hybridization model and density functional theory (DFT) calculations. Finally, we demonstrate that tuning of the Fermi level of Pt results in reduced or increased overpotentials in water splitting.

Tuning the Electronic Properties of Platinum in Hybrid-Nanoparticle Assemblies for use in Hydrogen Evolution Reaction.

Platinum is the best electrocatalyst for the hydrogen evolution reaction (HER). Here, we demonstrate that by contact electrification of Pt nanoparticle satellites on a gold or silver core, the Fermi level of Pt can be tuned. The electronic properties of Pt in such hybrid nanocatalysts were experimentally characterized by X-ray photoelectron spectroscopy (XPS) and surface-enhanced Raman scattering (SERS) with the probe molecule 2,6-dimethyl phenyl isocyanide (2,6-DMPI). Our experimental findings are corroborated by a hybridization model and density functional theory (DFT) calculations. Finally, we demonstrate that tuning of the Fermi level of Pt results in reduced or increased overpotentials in water splitting.

Sonocatalytic Degradation of Methylene Blue by a Novel SnO2-Fe3O4@MWCNT Hybrid Nanocatalyst Under Ultrasonic Irradiation

Sonocatalytic Degradation of Methylene Blue by a Novel SnO2-Fe3O4@MWCNT Hybrid Nanocatalyst Under Ultrasonic Irradiation

Highly oxidative desulfurization of thiophenic model fuels and real gasoline by Keggin‐type heteropolyanion immobilized on polyaniline and chitosan as an efficient organic–inorganic nanohybrid catalyst

AbstractTo obtain clean gasoline, a new nanohybrid catalyst (TPA@PAN@CH) was synthesized by immobilizing tungstophosphoric acid (TPA) on the surface of polyaniline (PAN) and chitosan (CH) polymers. The features of the materials were detected by FT‐IR, UV/vis, XRD, FE‐SEM, and EDX methods. The XRD patterns demonstrate that the average crystallite size of the TPA@PAN@CH is estimated to be approximately 45 nm, which corresponds to the results of the FE‐SEM. The catalytic performance of the TPA@PAN@CH was tested in the nano‐catalytic oxidative desulfurization (Ncat‐ODS) of gasoline and model fuels by H2O2/AcOH (volume proportion of 2:1) oxidizing agent. The best desulfurization outcomes were achieved by 0.1 g of the TPA@PAN@CH as a nanocatalyst at 35°C under mild reaction conditions. Based upon the above findings, the sulfur content could be declined from 0.4986 to 0.0193 wt%, which corresponds to performance of 96%. Mercaptan concentration decreased from 98 to 4 ppm, and the removal efficiency of model fuels declined in the order of DBT ≥ BT > Th. The high catalytic activity of TPA@PAN@CH was maintained for five cycles without significantly diminishing its performance. This work suggested the potential application of the TPA@PAN@CH for eliminating of hazardous sulfur compounds that significantly affect the efficacy of the Ncat‐ODS.

Electrocatalytic methane conversion to high value chemicals at ambient conditions

A key catalytic challenge in the electro-conversion of methane (CH4) is to partially oxidize CH4 to liquid products under ambient environment. This paper describes the electrocatalytic activity of mesoporous rutile titanium dioxide (r-TiO2) nanorods (NRs) and Pt loaded mesoporous rutile TiO2 nanohybrids (Pt/r-TiO2) NRs prepared with the one step hydrothermal approach. The usefulness of this technique is to encapsulate Pt nanoparticles (NPs) and utilize this material in the liquid-phase oxidation of CH4. This electrocatalytic reaction of CH4 with Na2CO3 electrolyte was examined over highly active Pt/r-TiO2 NRs catalysts consisting of pure rutile phase TiO2 having enough loading amount (10 wt%) of metallic Pt NPs. The surface modification of r-TiO2 with Pt NPs promotes the activation of CH4 and •OH that can support to generate methyl radical (•CH3). Afterwards CH3OH (50 µmol/g catalyst⋅h) and C2H5OH (36 µmol/mg catalyst⋅h) including small amount of propanol products are formed along with H2 gas (0.1 ± 0.02 vol%) using Pt/r-TiO2 at 1.5 V vs. Ag/AgCl electrode. High-resolution transmission electron microscopy proves the existence of 4 to 8 nm spherical-shaped Pt NPs on r-TiO2 NRs. This research work should act as a template for the study and design of metal loaded mesoporous metal oxide nanohybrid catalysts for the C − H bond activation to liquid products.

A new samarium complex of 1,3-bis(pyridin-3-ylmethyl)thiourea on boehmite nanoparticles as a practical and recyclable nanocatalyst for the selective synthesis of tetrazoles

Boehmite is a natural and environmentally friendly compound. Herein boehmite nanoparticles were primarily synthesized and, then, their surface were modified via 3-choloropropyltrimtoxysilane (CPTMS). Afterwards, a new samarium complex was stabilized on the surface of the modified boehmite nanoparticles (Sm-bis(PYT)@boehmite). The obtained nanoparticles were characterized using thermogravimetric analysis (TGA), energy dispersive X-ray spectroscopy (EDS), Brunauer–Emmett–Teller (BET), wavelength dispersive X-ray spectroscopy (WDX), scanning electron microscope (SEM), Fourier transform infrared spectroscopy (FT-IR), Inductively coupled plasma mass spectrometry (ICP-MS), dynamic light scattering (DLS), and X-ray diffraction (XRD) pattern. Sm-bis(PYT)@boehmite was used as an environmentally friendly, efficient, and organic–inorganic hybrid nanocatalyst in the homoselective synthesis of tetrazoles in polyethylene glycol 400 (PEG-400) as a green solvent. Notably, Sm-bis(PYT)@boehmite is stable and has a heterogeneous nature. Thus, it can be reused for several runs without any re-activation.

Z-scheme driven photocatalytic activity of CNTs-integrated Bi2S3/WO3 nanohybrid catalysts for highly efficient hydrogen evolution under solar light irradiation

Harvesting solar energy for the production of molecular hydrogen through photocatalytic approach is a clean and sustainable pathway to deal with the energy crisis and pollution. In this connection, direct Z-scheme interfaced noble metal free CNTs integrated Bi2S3-WO3 ternary composite was designed and developed through simple hydrothermal and wet impregnation strategies. This combination was manifested for the first time to tackle the photo-corrosion of Bi2S3 through Z-scheme heterojunction formation, and its effective contribution in the mitigation of charge carrier recombination was investigated. 9 wt% WO3 loaded Bi2S3 (WB-9) delivered a notable H2 production rate of 4.85 mmol.h−1.g-1cat over 5 vol% glycerol as a sacrificial reagent under simulated solar light irradiation. This enhancement was six folds higher than the pristine Bi2S3 photocatalytic activity. To enhance the reduction half-reaction further, electron mobility was regulated with CNT integration, which not only triggers the successive transport of electrons through its tubular channel, but also facilitate an excellent reduction co-catalyst to support rapid reduction of protons to form H2 molecules. Upon optimization of CNTs loading, 1 wt% CNTs loaded WB-9 (CWB-4) produced two-folds higher H2 production rates than WB-9, which is about 9.91 mmol.h−1. g−1cat. The observed efficiency, stability, and recyclability of CWB-4 attributed to the effective utilization of generated charge carriers across the system and suppressed photo-corrosion of Bi2S3 through the Z-scheme interface.