Potent Photocatalyst Research Articles

Metal–Organic Framework (MOF)‐based Single Atom Catalysts (SACs) for Photocatalytic Energy Conversion

AbstractRecently metal–organic frameworks (MOFs) have been demonstrated as potential precursors for obtaining single atom catalysts (SACs). Although SACs are attracting significant scientific attention due to their exceptional catalytic properties, the synthesis of SACs is still challenging due to their high surface free energy and this limits the growth of SACs. However, recent scientific research indicates that MOFs, due to their interesting structural feature, tunable pore size, high porosity, and exceptional thermal and chemical stability, can be an ideal candidate for the development of SACs. Current environmental crisis highly demands development of efficient photocatalysts for sustainable energy conversions such as photocatalytic hydrogen evolution, photocatalytic carbon dioxide, oxygen reduction, and so forth. MOF‐based SACs are emerging as most potent photocatalyst for such energy conversion. This review summarizes the advances in the field of MOF‐based SAC systems for photocatalytic energy conversions referred to above, along with mechanistic aspects. The complementarity of MOFs and SACs in the principle of photocatalysis have been elucidated. This review also seeks to offer an insight into the challenges involved and the future prospects of MOF‐based SAsystems.

In-situ construction of g-C3N4/LaPO4 S-scheme heterostructure with nitrogen vacancy for boosting photocatalytic reduction of CO2

It is a realizable way to enhance the performance of photocatalytic reduction of carbon dioxide by constructing S-scheme heterojunctions due to its unique interfacial structures. In this article, g-C3N4/LaPO4 heterojunctions with surface nitrogen vacancies were prepared by in-situ one-pot hydrothermal method. The experimental results show that the generation rate of carbon monoxide produced via the best g-C3N4/LaPO4 heterojunction is 145.8μmol g−1 h−1, which is 4.0 times and 11.2 times as large as pure g-C3N4 and LaPO4, respectively. The heterojunction structure is characterized by UPS, in situ XPS and DFT calculation. The construction of S-scheme heterojunction can efficiently promote the separation of photogenerated electron holes and improve the redox capacity to boost photocatalytic activity. Furthermore, nitrogen vacancy in g-C3N4/LaPO4 heterojunction could provide more reaction active sites, which is conductive to the absorption, distribution and activation of CO2 and H2O molecules. In summary, this advancement opens up a promising avenue for the development of more potent photocatalysts, offering potential solutions for environmental and energy-related applications.

Integrating Mo2C/C as cocatalyst into S-scheme Mo2C/C/Co0.5Cd0.5S heterojunction with spatial photocarrier separation for photocatalytic synergistic H2 evolution

Reasonable design and production of potent photocatalysts for sustainable H2 production from solar energy is one of the necessary strategies in the photocatalysis process. The S-scheme heterojunction exposes remarkable superiority in boosting light harvesting and progressing photocarrier separation efficiency in the photocatalyst. Here, new S-scheme heterojunction Mo2C/C/Co0.5Cd0.5S photocatalysts, including different weights of noble metal-free Mo2C/C nanostructures as cocatalysts, were successfully synthesized. As expected, the nanocomposite structures exhibited increased photocatalytic activity relative to single Co0.5Cd0.5S. The nanocomposite containing 5 wt% Mo2C/C exhibited an increased hydrogen production efficiency of 83.86 mmol g−1 h−1, which was 8.4 times higher than single Co0.5Cd0.5S (10.06 mmol g−1 h−1). This implies that for Co0.5Cd0.5S, Mo2C/C increases visible light absorption, facilitates photocarrier separation, and boosts the H2 evolution rate. Moreover, conductive carbon nanoparticles, electron mediators with strong interfacial interaction, serve as rapid photocarrier transfer bridges between Co0.5Cd0.5S and Mo2C. In summary, the superb efficiency of Mo2C/C/Co0.5Cd0.5S is accredited to the synergistic effect between Co0.5Cd0.5S and Mo2C/C, the creation of S-scheme heterojunction, which assists the separation of photocarriers and declines the recombination possibilities. This research ensures a reference and new profound insight for understanding and designing noble metal-free cocatalyst-assisted S-scheme heterojunctions for immensely efficient photocatalytic H2 production.

A new Zn(II)-based 3D MOF with PCU-like topology: Potent photocatalyst for nitrofurazone antibiotic degradation

Metal-organic frameworks (MOFs), a sub-class of coordination polymers, are versatile multidimensional materials that have the potential to serve as photocatalysts for the degradation of antibiotics found in wastewater. Herein, a new three dimensional (3D) Zn(II)-based MOF [Zn(TA)(bpyp)·3H2O] (1) (bypy = 2,5-bis(pyrid-4-yl)pyridine; H2TA = terephthalic acid) has been synthesized and characterized. The MOF 1 shows a 3D PCU-like topology and exhibits semiconducting properties with band gap of 3.34 eV and hence used as a photocatalyst for photodegradation of antibiotics viz. sulfasalazine (SLA), nitrofurazone (NFZ) and furazolidone (FZD) under simulated UV light irradiation. The photocatalytic results suggest that MOF 1 exhibits best photocatalytic activity for the photodegradation of nitrofurazone (NFZ) in 60 min time-span. The effects of initial concentration of NFZ, and photocatalyst dosage have been monitored for the photocatalytic performance of 1. The radical trapping experiments suggest that (holes) h+ and superoxide radical (O2·−) collectively catalyzes the photodecomposition of antibiotics. The possible mechanism for the antibiotic degradation by photocatalyst 1 have been proposed by integrating experiment with density of states (DOS) calculations and Hirshfeld surface analysis.

A Schottky/Z-Scheme Hybrid for Augmented Photocatalytic H2 and H2O2 Production.

The prodigious employment of fossil fuels to conquer the global energy demand is becoming a dreadful threat to the human society. This predicament is appealing for a potent photocatalyst that can generate alternate energy sources via solar to chemical energy conversion. With this interest, we have fabricated a ternary heterostructure of Ti3C2 nanosheet modified g-C3N4/Bi2O3 (MCNRBO) Z-scheme photocatalyst through self-assembly process. The morphological analysis clearly evidenced the close interfacial interaction between g-C3N4 nanorod, Bi2O3 and Ti3C2 nanosheets. The oxygen vacancy created on Bi2O3 surface, as suggested by XPS and EPR analysis, supported the Z-scheme heterojunction formation between g-C3N4 nanorod and Bi2O3 nanosheets. The collaborative effect of Z-scheme and Schottky junction significantly reduced charge transfer resistance promoting separation efficiency of excitons as indicated from PL and EIS analysis. The potential of MCNRBO towards photocatalytic application was investigated by H2O2 and H2 evolution reaction. A superior photocatalytic H2O2 and H2 production rate for MCNRBO is observed, which are respectively around 5 and 18 folds higher as compared to pristine CNR nanorod. The present work encourages for the development of a noble, eco-benign and immensely efficient dual heterojunction based photocatalyst, which can acts as saviour of human society from energy crisis.

Reduced graphene oxide supported Bismuth-Iron mixed oxide nanocomposite: A potent photocatalyst for crystal violet dye degradation and antimicrobial application

The nanocomposites of rGO-[BixFe(1-x)]2O3 (x=0.02, 0.05, 0.10 and 0.20) are successfully synthesized with the help of a cost-effective co-precipitation procedure. Influence of Bi on to the magnetic, optical, microstructural and antimicrobial properties of Fe2O3 are investigated. The presence of pure α-Fe2O3 is being witnessed through the characteristic intensity of XRD peak where phase impurity is not noticed up to 10 % of Bi loading. Presence of various defects have been realized in the sample from PL spectra. The direct band gap of the adsorbent nanocomposite with Bi loading up to 10 % with that of α-Fe2O3 is found to be 2.51 eV and it may be taken as a suitable photocatalyst of choice towards the photodegradation of Crystal Violet with 97.69 % by maintaining the pH-10 and time-60 min as optimum condition. Adsorption capacity (qm) and rate constant (kapp) are found to be 28.50 mg/g and 0.0473 min−1 respectively. The antimicrobial analysis of the synthesized material signifies its antibacterial activity against Staphylococcus aureus (Gram +Ve) and Klebsiella pneumonia (Gram −Ve). On the basis of our finding, the synthesized nano composite may be the materials of choice for the optical device application, memory storage device as well as in the biomedical application.

A new 3D Zn(II)‐based coordination polymer with kgd topology as potent photocatalyst for antibiotic degradation

A new coordination polymer (CP) with composition [Zn3(bpyp)2(TCB)2(H2O)2]n (1) has been engendered by performing reaction of Zn(II) with 1,3,5‐tris‐(4‐carboxyphenyl)benzene (H3TCB) and 2,5‐bis(pyrid‐4‐yl)pyridine (bpyp) under solvothermal condition. The single crystal X‐ray diffraction analysis for 1 suggests kgd topological behavior having resemblance with a tessellation composed of diamond shapes arranged in a star pattern and represented by the Schläfli symbol {41}2{42·62·81}. This newly designed CP exhibits optical band gap of 2.92 eV and employed as photocatalyst for photodegradation of antibiotics, namely, nitrofurazone (NFZ), chloramphenicol (CAP), sulfasalazine (SLA), oxytetracycline (OXY), and furazolidone (FZD). Among these antibiotics, 1 displays best photocatalytic activity against the photodegradation of NFZ and under optimized conditions viz. photocatalyst dosage of 15 mg, and initial NFZ concentration of 40 ppm, the CP 1 displays best catalytic performance and photo‐decomposed 93.04% NFZ with pseudo first order rate constant k of 0.04502 min−1 in 1 h. The likely photocatalytic mechanism has been evaluated using theoretical calculations.

Synthesis and characterization of Fe-doped CuO nanoparticles: Catalytic efficiency in crystal violet dye degradation and exploration of electrical properties

In recent times, environmental pollution has become a pressing issue. Different methods have been developed to detach hazardous materials from H2O bodies. Among these techniques, photo-catalysis has emerged as a low-cost and advanced method. However, finding a potent photocatalyst has been a topic of considerable research. Our study prepared CuO from copper acetate using hydrothermal treatment in an autoclave at 170 ºC for 14 hours. We introduced various quantities of Fe by adding FeSO4 mixture to Cu (CH3COO)2, following the identical method for preparing CuO. The resulting precipitate was cleaned with deionized H2O and dried at 100 °C. The prepared substance was then heated at 450 ºC in a muffle furnace for 60 minutes. We characterized the manufacture of photocatalysts utilizing various techniques such as Ultraviolet (UV), FT-IR, SEM, EDX, and XRD. Our Ultraviolet (UV) spectrum analysis helped us recognize the adsorption spectroscopic analysis of un-doped and doped CuO with various ratios of Fe. FTIR spectroscopic analysis helped us identify functional groups in CuO NPs. Our XRD study showed the monoclinic composition of copper oxide nanoparticles. The SEM picture suggested that NPs exist in a spherical shape. We studied the catalytic activity of synthesized NPs concerning crystal violet (CV) colorant degradation below a direct ray of light irradiation. Our results showed that the degradation productiveness, as compared to CV colorant, was about 93.52% in 180 min. This research is of great importance in the quest for effective and sustainable solutions to environmental problems. The examination of electrical properties highlighted the promising aspects of Fe-doped CuO, particularly at 6% doping. This variant demonstrated superior dielectric parameters, lower tangent loss, semiconductor-like impedance behavior, and enhanced electrical conductivity, emphasizing its potential for applications in electrical and energy storage domains.

An exhaustive exploration of Zn0.15Sn0.85(Se0.95S0.05)2 crystal-based photodetector and its potential application as a photocatalytic material

The research pioneers the exploration of synthesized quaternary Zn0.15Sn0.85(Se0.95S0.05)2 (ZSSS) crystals, demonstrating remarkable efficacy as optoelectronic switching devices and potent photocatalysts. The ZSSS photodetector recorded a stable photoresponse with remarkable rapid rise and decay times. The Langmuir-Hinshelwood kinetic model was used to look at the photocatalytic activity at different methylene blue concentrations. The researchers grew highly pure ZSSS crystals using the direct vapour transport (DVT) method. Field effect scanning electron microscopy (FESEM) and high-resolution transmission electron microscopy (HRTEM) images reveal the layer growth mechanism in the grown crystals. The structural analyses of the grown crystals were carried out using an X-ray diffraction (XRD) pattern and temperature-dependent Raman spectroscopy. The Lorentzian function was fitted to experimental data to carry out the temperature-dependent Raman analysis. The grown crystals exhibit a direct optical bandgap of 1.69 eV. The electrical analyses explain the semiconducting nature of the crystals.

Sonication supported green modulation of Fe:MoO3/g-C3N4 heterojunction as solar light sensitive photocatalyst for dye degradation and photoelectrochemical water splitting

The concerns of dye in an aquatic system associated with acute toxicity and carcinogenicity, and the increase in demand for hydrogen production has led to a keen interest in advancing solar driven methodologies utilizing potent photocatalysts to address environmental concerns through sustainable remediation practices. In this pursuit, we synthesized a heterostructure comprised of Fe doped MoO3 (Fe:MoO3), anchored on g-C3N4 sheet as a photocatalyst denoted as Fe:MoO3/g-C3N4, employing a sonication supported green synthesis method with the aid of Murraya paniculata leaf extract. We explored structural, morphological, and surface characteristics using various analytical techniques, including X-Ray diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy, UV–visible spectroscopy, Field emission scanning electron microscopy (FE-SEM) and High-resolution transmission electron microscopy (HR-TEM), X-Ray photoelectron spectroscopy, and BET for a comprehensive surface analysis. The outcomes highlighted the exquisitely oriented and interconnected arrangement of MoO3 nano rods ensconced within a piled layer of g-C3N4. The XRD patterns unveiled the coexistence of g-C3N4 and Fe:MoO3 within the heterojunction structure. FESEM and HRTEM image analysis of Fe:MoO3/g-C3N4 heterojunction reveals a g-C3N4 nanosheet wrapping the Fe:MoO3 nanoparticles with the formation of nanorods of MoO3 with an average thickness of 9.46 nm containing circular Fe nanoparticles with a mean diameter of 8.97 nm. This intricate configuration resulting in a decrease of the size of the nanoparticle caused by effective sonication-supported green modulation configuration facilitated an optimized charge flow, contributing to the elevated photo assisted catalytic performance of the heterojunction. The Fe:MoO3/g-C3N4 semiconductor heterojunction exhibited a considerable surface area and pore volume, inherently amplifying the sites of the activity on the surface and thereby enhancing photoactivity. As opposed to both g-C3N4 and the Fe:MoO3 nanoparticles, the Fe:MoO3/g-C3N4 semiconductor heterojunction showcased enhanced photocatalytic effectiveness in the degradation of dye Crystal violet (CV). Under optimized circumstances, the photo assisted degradation of dye CV by the semiconductor heterojunction adhered to pseudo-first-order kinetics. The active species responsible for the photo assisted degradation process is identified as •O2−. These findings not only emphasize the enhanced efficacy of the developed semiconductor heterojunction but also reveal its potential for addressing the environmental challenges posed by dye CV contamination through prolonged and efficient photocatalytic remediation practices. A marked improvement in both photo assisted catalytic and photoelectrochemical (PEC) water splitting activities under visible light exposure was showcased. The augmented performance of the Fe:MoO3/g-C3N4 semiconductor heterojunction in photodegradation and PEC water splitting activities can be attributed to the extended absorption of visible light. Additionally, the synergistic influence of g-C3N4, contributes positively to the separation of charges and expedites the transfer efficiency of photogenerated charge carriers. This synergy enhances the overall effectiveness of the nanoparticles in harnessing visible light for efficient water-related processes.

Designing sustainable porous graphene-CaTiO3 nanocomposite for environmental remediation

In the pursuit of sustainable energy and environmental solutions, photocatalysis has emerged as a transformative technology, harnessing the power of light to drive chemical transformations. Among the myriad photocatalytic materials, calcium titanate (CaTiO3) stands out as a promising candidate, holding the potential to revolutionize the landscape of photocatalysis. To further improvise the efficiency of CaTiO3 in this work, porous graphene-CaTiO3 nanocomposite was synthesized by a straightforward solvothermal method and its photocatalytic activity was tested for the degradation of methylene blue dye under visible light. The synthesized sample exhibited 98.1% degradation in 40 min with excellent cyclic stability. Experimental and computational analysis attributed the enhanced performance to the strong chemical interaction of CaTiO3 cuboids with PG sheets via Ti-O-C bond which led to efficient electron hole separation leading to enhanced lifetime of the charge carriers. This along with reduced band gap and increased surface area made the material a potent photocatalyst for the degradation of dyes in short duration.

Unveiling the potential of MOF-based single-atom photocatalysts for the production of clean fuel and valuable chemical.

Harnessing solar energy through photocatalysis has excellent potential for powering sustainable chemical production, supporting the United Nations' environmental goals. Single-atoms (SAs) dispersed on catalyst surfaces are gaining attention for their highly active and durable nature. Metal-organic frameworks (MOFs) can provide enough reactive sites to sustain selectivity and durability over time because of their tunable channels and functional groups. Owing to their organized structures, MOFs are ideal platforms for securing individual atoms and promoting solar-driven reactions. Few reviews have, however, reflected the possibility of combining MOFs and SAs to produce potent photocatalysts that may produce clean fuels and valuable chemicals. This review provides a general overview of methods for combining MOFs and SAs to generate photocatalysts. The challenges associated with these MOF-based single-atom systems are also critically examined. Their future development is discussed as continued refinement helps to more fully leverage their advantages for boosting photocatalytic performances - turning sunlight into chemicals in a manner that supports sustainable development. Insights gained here could illuminate pathways toward realizing the profound potential of MOF-based single-atom photocatalysts to empower production driven by renewable solar energy.

Photocatalytic aerobic α-oxygenation of amides to imides using a highly durable decatungstate tetraphenylphosphonium salt.

Decatungstate is a potent photocatalyst for hydrogen atom transfer (HAT) but faces degradation issues when using a typical tetra-n-butylammonium salt. Herein, we employed tetraphenylphosphonium as a countercation to yield a highly durable and efficient HAT photocatalyst, enabling α-oxygenation of amides to their corresponding imides using O2 as an oxidant.

ZnO-ZnS Heterostructure as a Potent Photocatalyst in the Preparation of Some Substituted Chromenes and Remarkable Antigastrointestinal Cancer Activity.

The nanosized hybrid material ZnO-ZnS was synthesized using the well-known sol-gel method, as a simple and environmentally friendly procedure. The material was then characterized using various techniques including FESEM, TEM, UV-vis, DRS, EDS, XRD, and FT-IR. The characterization studies revealed the generation of ZnO-ZnS nanoparticles with a mean size of around 25 nm. Moreover, DRS analysis provided a band gap of 3.05 eV for this nanomaterial. The photocatalytic properties of the ZnO-ZnS heterojunction was investigated in the synthesis of some substituted chromenes under mild reaction conditions. The results showed that the prepared nanophotocatalyst exhibits significantly higher activity compared to its individual components (ZnO and ZnS) and provides 73-87% yield with 0.01 g of ZnO-ZnS after 30 min. In addition, the nanophotocatalyst demonstrated a high reusability in the desired condensation reaction. The enhanced photocatalytic activity of ZnO-ZnS can be attributed to the slower recombination of the electron-hole pairs in this semiconductor material. The reactive species OH•, •O2-, and h+ are believed to play important roles in the photocatalytic system. Furthermore, cellular toxicity of ZnO-ZnS nanoparticles was evaluated on HCT-116 human gastrointestinal cancer cell line by MTT assay. The results proved a distinct reduction of cell viability, proofing cytotoxicity of nanoparticles on the cancer cells. This study highlights the potential of the nanoparticles against gastrointestinal cancer.

New 5,5-(1,4-Phenylenebis(methyleneoxy)diisophthalic Acid Appended Zn(II) and Cd(II) MOFs as Potent Photocatalysts for Nitrophenols.

Metal-organic frameworks (MOFs) are peculiar multimodal materials that find photocatalytic applications for the decomposition of lethal molecules present in the wastewater. In this investigation, two new d10-configuration-based MOFs, [Zn2(L)(H2O)(bbi)] (1) and [Cd2(L)(bbi)] (2) (5,5-(1,4-phenylenebis(methyleneoxy)diisophthalic acid (H2L) and 1,1'-(1,4-butanediyl)bis(imidazole) (bbi)), have been synthesized and characterized. The MOF 1 displayed a (4,6)-connected (3.43.52)(32.44.52.66.7) network topology, while 2 had a (3,10)-connected network with a Schläfli symbol of (410.511.622.72)(43)2. These MOFs have been employed as photocatalysts to photodegrade nitrophenolic compounds, especially p-nitrophenol (PNP). The photocatalysis studies reveal that 1 displayed relatively better photocatalytic performance than 2. Further, the photocatalytic efficacy of 1 has been assessed by altering the initial PNP concentration and photocatalyst dosage, which suggest that at 80 ppm PNP concentration and at its 50 mg concentration the MOF 1 can photo-decompose around 90.01% of PNP in 50 min. Further, radical scavenging experiments reveal that holes present over 1 and ·OH radicals collectively catalyze the photodecomposition of PNP. In addition, utilizing density of states (DOS) calculations and Hirshfeld surface analyses, a plausible photocatalysis mechanism for nitrophenol degradation has been postulated.

Harnessing Bio-Immobilized ZnO/CNT/Chitosan Ternary Composite Fabric for Enhanced Photodegradation of a Commercial Reactive Dye.

Growing demand for sustainable wastewater treatment drives interest in advanced photocatalytic materials. Immobilized photocatalysts hold potential for addressing industrial wastewater organic pollutants, offering substantial surface area, agglomeration prevention, and easy removal. In this study, we successfully immobilized ZnO and carbon nanotubes onto a textile substrate through bilateral esterification and explored their effectiveness as a potent photocatalyst for degrading of commercial textile colorant reactive blue 4 (RB-4) colorant. Findings demonstrated significant improvements in photocatalytic performance upon integrating ZnO and CNTs into the fabric, coupled with chitosan immobilization. The immobilization process of ZnO and CNTs onto the substrate was elucidated through a proposed reaction mechanism, while the appearance of carbonyl peaks at 1719.2 cm-1 in the composite fabric further confirmed bilateral esterification. The as-developed immobilized nano-catalyst exhibited remarkable photocatalytic efficiency with an impressive 93.54% color degradation of RB-4. This innovative approach underscores the immense potential of the ternary immobilized (ZnO/fCNT/chitosan) composite fabric for efficient photocatalytic degradation in textile coloration processes. Exploring the early-stage development of immobilized photocatalysts contributes to safer and more eco-friendly practices, addressing pressing environmental challenges effectively.

NIR-Triggered SrSnO3 -photosynthesized nanocatalyst: A potent anticancer agent against triple negative breast cancer cells

The major systemic therapeutic option for Triple Negative Breast Cancer (TNBC) is chemotherapy. TNBC often responds well to chemo, however, chemotherapy carries toxic adverse effects and content-limited interventional efficiency. Thereby, a drug-free treatment paradigm is imperative, in which synthetic polymers spontaneously display efficient anticancer efficacy without the use of conventional chemotherapeutic agents. Aiming at the goal to treat TNBC, SrSnO3 nanoparticles were devised as a nanocatalyst to accomplish near infrared (NIR) photocatalytic production of oxidative holes for achieving hole therapy. An inexpensive sol-gel method was employed in this study to synthesize SrSnO3 nanoparticle using strontium chloride hexahydrate and stannous chloride dihydrate. Transmission electron microscopy (TEM), X-ray diffraction (XRD), Field emission scanning electron microscopy (FE-SEM) and X-ray photoelectron spectroscopy (XPS) analyses were used to characterize the synthesized SrSnO3 nanoparticles while Density Functional Theory (DFT) was used to study the nanoparticle at atomistic level and the band gap was calculated to be 1.84 eV using Perdew−Burke−Ernzerhof (PBE) functionals. The anticancer effect of SrSnO3 nanoparticle was tested against TNBC cell line MDA-MB-231 at different concentration (10–50 μg/mL) with near infrared (NIR) irradiation while cells without any treatment or treatment with only SrSnO3 or NIR served as controls. Under NIR irradiation, the IC50 value was found to be 40 μg/mL achieving 50% cell death with augmented release of reactive oxygen species (ROS) over time. Reduced and oxidized glutathione (GSH and GSSG, respectively) serve as cellular redox buffers and protect cells from ROS mediated damage. Nearly 18.6% reduced glutathione (GSH) was found to be consumed with 5 min of NIR irradiation that was augmented to 66.5% of GSH when exposure time was increased to 10 min suggesting a prooxidant mediated death of cancer cell line. The results suggested SrSnO3 nanoparticle is a potent photocatalyst when triggered by NIR and can enable highly effective and biosafe hole-mediated treatment for TNBC.

Facile fabrication of Pluronic-mediated copper nanoparticles using microwave techniques and their application as the photocatalysts for various organic dyes degradation

Pluronic-mediated copper nanoparticles (CuNPs) were fabricated using the reducing agent sodium borohydride in the micellar media of different Pluronics (L121, P123, and F127) using cost-effective microwave techniques. The microwave-irradiation used to create CuNPs has been optimized. All Pluronic-mediated CuNPs fabricated emit red light and have been thoroughly characterized using a range of advanced techniques. The results showed that the hydrophilic PEO and hydrophobic PPO parts of the Pluronic have a countable impact on the particle size and stability of the CuNPs. When compared to the other two Pluronic micellar media, the Pluronic F127-mediated CuNPs (CuNPsF7) performed better in terms of uniformity, size reduction, and stability. In this context, CuNPsF7 has been investigated as a powerful photocatalyst for the degradation of textile anionic (Congo red and methyl orange) and cationic (Methylene blue and rhodamine B) dyes. When compared to blank CuNPs, the results confirmed that the CuNPsF7 followed pseudo-first-order kinetics and significantly increased the rate and efficiency of dye degradation. In conclusion, the Pluronic-mediated CuNPs serve as potent photocatalysts to remove organic dyes in the treatment of waste water from textile industries.

Non-graphitized carbon/Cu2O/Cu0 nanohybrids with improved stability and enhanced photocatalytic H2 production

Cu2O is a highly potent photocatalyst, however photocorrosion stands as a key obstacle for its stability in photocatalytic technologies. Herein, we show that nanohybrids of Cu2O/Cu0 nanoparticles interfaced with non-graphitized carbon (nGC) constitute a novel synthesis route towards stable Cu-photocatalysts with minimized photocorrosion. Using a Flame Spray Pyrolysis (FSP) process that allows synthesis of anoxic-Cu phases, we have developed in one-step a library of Cu2O/Cu0 nanocatalysts interfaced with nGC, optimized for enhanced photocatalytic H2 production from H2O. Co-optimization of the nGC and the Cu2O/Cu0 ratio is shown to be a key strategy for high H2 production, > 4700 μmoles g−1 h−1 plus enhanced stability against photocorrosion, and onset potential of 0.234 V vs. RHE. After 4 repetitive reuses the catalyst is shown to lose less than 5% of its photocatalytic efficiency, while photocorrosion was < 6%. In contrast, interfacing of Cu2O/Cu0 with graphitized-C is not as efficient. Raman, FT-IR and TGA data are analyzed to explain the undelaying structural functional mechanisms where the tight interfacing of nGC with the Cu2O/Cu0 nanophases is the preferred configuration. The present findings can be useful for wider technological goals that demand low-cost engineering, high stability Cu-nanodevices, prepared with industrially scalable process.

A new 3,4-connected Zn(II)-based nitroisophthalic acid appended coordination polymer as potent photocatalyst for dye degradation

In the presented investigation a new Zn(II)-based coordination polymer (CP) with formula [Zn2(bpyp)(nip)2·1.5H2O] (1) have been synthesized using 2,5-bis(pyrid-4-yl)pyridine (bypy) and 5-aminoisophthalic acid (H2L-NH2) ligands and characterized. The single crystal X-ray diffraction suggests that CP 1 possess 3D binodal (3,4)-connected network with the Schläfli symbol (63)(65.8) and can be used as the effective photocatalyst for the photodegradation of methyl blue dye amongst viz. acid chrome blue (ACB), methyl blue (MB) and methyl violet (MV) under UV irradiation under UV light irradiation. Amongst all three dye, 1 exhibits best photodegradation of MB and hence effects of initial MB concentration and photocatalyst dosage on the photocatalytic performance of 1 have been studied. The studies suggest that 1 exhibits best photocatalysis at 25 ppm MB concentration and 25 mg dosage of 1. Also, radical trapping investigation suggest that O2·− is the main active species responsible for MB dye photodegradation. Further, density of states (DOS) and Hirshfeld surface analyses have been employed to offer a mechanistic pathway for 1 assisted degradation of MB dye.