MoO3 Nanoparticles Research Articles

Fabrication of CuS-MoO3 nanocomposite for high-performance photocatalysis and biosensing

The design and development of highly efficient nanostructure materials for photocatalytic and electrochemical applications is very necessary. In this study, CuS-MoO3 nanocomposite (NCs) was fabricated using a simple wet impregnation process and the photodegradation potential for 8 major hazardous dyes and electrochemical sensing of Dopamine was investigated. X-ray diffraction (XRD), Fourier transform - Infrared spectroscopy (FTIR), UV-Vis spectroscopy (UV-Vis), Photoluminescence spectroscopy (PL), Scanning Electron Microscopy (SEM), Energy-dispersive X-ray spectroscopy (EDX) and Transmission Electron Microscopy (TEM) were employed for characterization. Fabricated NCs are made up of CuS in the hexagonal phase and MoO3 in the orthorhombic phase, both of which react to UV light. Optical and electrochemical impedance spectroscopy (EIS) results show that improved photocatalytic performance is related to increased UV light spectrum sensitivity, inhibited charge carrier recombination, and decreased band gap energy in the NCs. Experimental findings showed that CuS-MoO3 (CMS) NCs had substantially more photocatalytic degradation activity than pure MoO3 and CuS nanoparticles (NPs). The prepared CMS NCs were then used for electrochemical analysis of Dopamine (DA). Electroanalytical results showed that the CMS NCs had enhanced electrochemical activity towards DA. The constructed sensor has a limit of detection of (6.61 µM) and proved that it is capable of being a sensor.

Controlled nucleation of ultrasmall MoO3 nanoparticles on defective graphene for enhanced ammonia efficiency.

Ultrasmall nanoparticles on nanocarbons enhance the electrocatalytic nitrogen reduction (NRR) efficiency. Herein, we demonstrate a novel method for depositing MoO3 nanoparticles on defective graphene, achieving a high faradaic efficiency (FE) of 43.1% at -0.2 V vs. RHE.

Molybdenum-Oxide-Modified PEDOT:PSS as Efficient Hole Transport Layer in Perovskite Solar Cells.

Over the last ten years, there has been a remarkable enhancement in the power conversion efficiency (PCE) of perovskite solar cells (PSCs), with poly (3,4-ethylenedioxythiohene):poly (styrenesulfonate) (PEDOT:PSS) emerging as a prevalent choice for the hole transport layer (HTL). Nevertheless, the evolution of the widely utilized PEDOT:PSS HTL has not kept pace with the swift advancements in PSC technology, attributed to its suboptimal electrical conductivity, acidic nature, and inadequate electron-blocking performance. This study presents a novel approach to enhance the HTL by introducing molybdenum oxide (MoO3) into the PEDOT:PSS, leveraging the conductivity and solution processing compatibility of MoO3. Two methods for MoO3 integration were explored: an ammonium molybdate tetrahydrate (AMT) precursor and the direct addition of MoO3 nanoparticles. The carrier dynamics of PSCs modified by MoO3 are significantly optimized. Therefore, the PCE of the device modified by AMT and molybdenum oxide is increased to 18.23 and 19.64%, respectively, and the stability of the device is also improved. This study emphasizes the potential of MoO3 in contributing to the development of more efficient and stable PSCs.

Vibration and Noise of Diesel engine Using Calophyllum inophyllum Biodiesel and MoO3 nanoparticles: Experimental and machine learning study

The current study deals with the evaluation of vibrations and noise generated by a diesel engine powered by Calophyllum inophyllum biodiesel blend (B20) and molybdenum trioxide (MoO3) nanoparticles, predicted using machine learning algorithms. The nanoparticles were spread out in B20 at a level of 75 ppm, along with a surfactant and a dispersant to make sure they mixed evenly with the fuel samples. The stability of the nanoparticles was then tested using the principle of photo spectroscopy and it was found that the stability of nanoparticles to which surfactants and dispersants had been added was increased. The experiment with the diesel engine was carried out to evaluate the vibrations and noise by varying different loads (3, 6, 9, and 12 kgf) and injection pressures (200, 220, and 240 bar). The vibrations and noise intensity were reduced with B20 compared to normal diesel and a further reduction was observed by adding nanoparticles together with the dispersant. With increasing load, the RMS velocity and the RMS noise also increased, but these decreased with increasing injection pressure. The most favourable result for RMS velocity and RMS noise was B20+MoO3 75 ppm+ Dispersant 75ppm. At an injection pressure of 240 bar and a full load of 12 kgf, the RMS velocity was 0.568 m s-1 and 55.265 dB, which corresponds to an improvement of 28.76 % and 9.78 % respectively compared to conventional diesel for B20+MoO375ppm+ Dispersant 75ppm. Finally, the entire experimental data of 60 were predicted using various machine learning (ML) algorithms, such as Random Forest (RF), Decision Trees (DT), Artificial Neural Networks (ANNs), Support Vector Machines (SVM) and XG Boost and the predicted results correlated well with the experimental values. All algorithms have shown a good association, but XGBoost has shown a better correlation coefficient (R2). The R2 of each algorithm is in the range of 0.94–0.99, the MRE and RSME are also in the significant range for both RMS velocity and RMS noise.

Comparative study of CO adsorption on Au, Cu, MoO2 and MoS2 2D Nanoparticles

This study focuses on a comparative analysis of the electronic properties of triangular, irregular hexagonal, and octagonal 2D nanoparticles containing 10, 12, and 14 motifs, made of Au, Cu, MoO2, and MoS2. The investigation was carried out using density functional theory. The formation energies and vibrational frequencies demonstrate that the 2D nanostructure configurations can exist as stable structures. Edge atoms with lower coordination numbers than central atoms, are the preferred sites for CO adsorption. Using orbital-weighting dual descriptors calculated from Fukui functions enabled the identification of a majority nucleophilic attack sites in Au and Cu nanoparticles, while MoO2 and MoS2-based nanoparticles present almost as many electrophilic sites as nucleophilic sites. The charge transferred between the nanostructures and the CO molecule and the redistribution of the projected density of states were used to assess the strength of interfacial bonds and the nature of the fundamental interaction involved in the bonding.

Facile synthesis of Fe/W co-doped MoO3 nanomaterial for proficient photocatalytic, enhanced sensing, superior luminescence and antioxidant activities

We report a new, easy and environment friendly defects engineered approach to develop defect-rich Fe/W co-doped MoO3 nanoparticles (Fe,W-MoO3 NPs) for a variety of applications. The solution combustion process entails using Millettia peguensis flowers extract as a unique fuel for the synthesis of Fe,W-MoO3 NPs. The synthesized NPs were characterized by various physical techniques. As prepared NPs were well examined for photocatalytic methylene blue (MB) dye degradation, electrocatalytic nitrite sensing, antioxidant and luminescence performances. Under visible light irradiation, Fe,W-MoO3 NPs exhibit outstanding photocatalytic performance towards MB dye degradation. Complete degradation of MB dye was demonstrated by the photocatalyst within a short span of 30 min. Cyclic voltammetry (CV) and linear sweep voltammetry studies were carried out to assess the electrocatalytic performance of as synthesized NPs. The Fe,W-MoO3 fabricated electrode manifested substantial nitrite sensing activity with LOD of 23.36 ± 1.17 µM. Fe,W-MoO3 nanoparticles demonstrated significant DPPH antiradical properties with IC50 of 394.33 ± 19.17 μg/mL. Also, as synthesized NPs exhibited significant luminescence activity portraying it as an efficient luminescent material. Thus, the current work manifests an inexpensive and sustainable green synthetic approach for large-scale synthesis of multifaceted Fe,W-MoO3 NPs.

MoO3 Nanoparticles for enhanced photocatalysis, antioxidant activity and some selected biomedical applications: Perioria pinnatum leaf extract assisted with green synthesis and Characterization

Molybdenum oxide nanoparticles were prepared in a single step by a solution combustion reaction using ammonia molybdenum powder as precursor and Perioria pinnatum leaf powder as a novel fuel. Crystalline phase and morphology of the products were studied systematically characterized by PXRD, FESEM-EDS, UV-Visible, FESEM and FT-IR analysis techniques. Results show a variety of MoO3 nanoparticles within the size range of 10–80 nm. Furthermore, micro rods and micro sheets were also obtained through this method whose length varied in the order of microns. The synthesized MoO3 nanoparticles as versatile biological agents.

Microwave-assisted synthesis and functionalization of nanocrystalline molybdenum trioxide for enhanced antimicrobial and photocatalytic activity

Molybdenum Trioxide nanoparticles (MoO3) were synthesized using ammonium heptamolybdate tetrahydrate [(NH4)6Mo7O24·4H2O] as the primary precursor via the microwave-assisted method and subsequently functionalized with surfactants such as Cetyltrimethylammonium bromide (CTAB), Sodium n-dodecyl sulfate (SDS), and Thioglycolic acid (TGA). The characterization involved X-ray diffraction, field emission scanning electron microscopy with energy-dispersive X-ray spectroscopy, Fourier-transform infrared spectroscopy, and UV–Visible spectroscopy, revealing hexagonal plate-like morphology, UV absorbance at 202–216 nm with a band gap of 4.2 eV, and a crystalline structure with a 44 nm size calculated by the Scherrer's equation. The synthesized pure (MoO3) and functionalized molybdenum trioxide nanoparticles (FMoO3) were tested for antibacterial activity against gram-positive Staphylococcus aureus and gram-negative Salmonella typhi. Furthermore, MoO3 and FMoO3 also demonstrated enhanced antifungal activity against the fungi Aspergillus niger (Accession No. MZ435922) and Aspergillus fumigatus (Accession No. MZ435863). Photocatalytic experiments demonstrated significant degradation of malachite green dye under UV light irradiation, notably with SDS functionalized MoO3 achieving 98.17 % degradation rate within 20 min, with a linear rate constant of 0.20343 min−1. These findings highlight the potential of MoO3 and FMoO3 nanoparticles as effective antimicrobial agents and their suitability for water purification due to their low toxicity.

A comprehensive analysis: The effects of 100 MeV Ni7+ ion irradiations on the structural integrity of MoO3 thin films

An effort has been made to comprehensively study the structural modification of the molybdenum trioxide (MoO3) thin film with 100 MeV, Ni7+. The MoO3 nanoparticles were synthesized by hydrothermal method and thin film of MoO3 was fabricated by spin coating technique. MoO3 thin film was subjected to irradiation with 100 MeV, Ni7+ beam with various fluences of 5 × 1012, 1 × 1013, and 3 × 1013 ions cm−2. The structural changes induced by ion beam irradiation were characterized using XRD diffraction, Raman, Fourier Transforms Infrared Spectroscopy (FTIR) UV–visible spectroscopy, and Atomic Force Microscopy (AFM). The synthesized thin film showed an orthorhombic phase and the average crystallite size was 63.8 nm of the pristine sample. it is observed that the crystallinity decreases after irradiation. The Raman study confirmed the XRD findings and also showed that after exposure, intensity of the Raman peaks decreased and the width of the spectra expanded due to a decrement in the crystallinity. The bandgap of the thin films decreased after irradiation as the ion fluence increased up to 3 × 1013 ions cm−2. The findings showed that the ion beam irradiation was directly accountable for the amorphization and lattice defect development in the MoO3 thin films.

A Highly Selective Acetone Sensor Based on Coal-Based Carbon/MoO2 Nanohybrid Material.

High temperature represents a critical constraint in the development of gas sensors. Therefore, investigating gas sensors operating at room temperature holds significant practical importance. In this study, coal-based porous carbon (C-700) and coal-based C/MoO2 nanohybrid materials were synthesized using a simple one-step vapor deposition and sintering method, and their gas-sensing performance was investigated. The gas-sensing performance for several VOC gases (phenol, ethyl acetate, ethanol, acetone, triethylamine, and toluene) and a 95% RH high-humidity environment were tested. The results indicated that the C/MoO2-450 sample sintered at 450 °C exhibited excellent specific selectivity towards acetone at room temperature, with a response value of 4153.09% and response/recovery times of 10.8 s and 2.9 s, respectively. Furthermore, the C/MoO2-450 sample also demonstrated good repeatability and long-term stability. The sensing mechanism of the synthesized materials was also explored. The superior gas-sensing performance can be attributed to the synergistic effect between the porous carbon and MoO2 nanoparticles. Given the importance of enhancing the high-tech and high-value-added utilization of coal, this study provides a viable approach for utilizing coal-based carbon materials in detecting volatile organic compounds at room temperature.

Introduction of bimetallic oxide-modified carbon nanotubes for boosting the energy storage performance of NiCo-LDH based in-plane micro-supercapacitors on paper

In-plane micro-supercapacitors (IMSCs) have greater promise for use in flexible wearable electronics than traditional stacked configurations due to their ease of integration and conformability. Nickel-cobalt layered double hydroxide (NiCo-LDH) has garnered significant interest as a stellar material for supercapacitors because of its affordable price, regular morphology, and high theoretical capacity. Unfortunately, the intrinsic poor conductivity of LDH materials prevents supercapacitors from achieving long-term stable cycling and the desired energy density. This research successfully applies the self-templated approach to prepare carbon nanotubes (CNTs) with heterogeneous architectures and numerous phase interfaces, thereby mitigating this disadvantage. Carbon nanosheets adorned with WO2 and MoO2 nanoparticles assemble the CNT with a typical three-dimensional structure. When combined with LDH in a suitable ratio, the composite electrode’s conductivity significantly improves, providing increased capacity and cycling stability. Compared to commercial CNTs, the larger size of the prepared WO2/MoO2@P, N-CNTs serves a superior supporting and connecting role, thereby preventing the NiCo-LDH from aggregating. Under the best conditions, the composite electrode demonstrates a capacity of 1237 C/g at 1 A g−1 and an optimal capacity retention of more than 92%. For the IMSC devices, the composite materials as the positive electrode achieve an energy density of 0.0590 mWh cm−2, and no capacity degradation is observed after 10,000 cycles. In addition, bending tests have demonstrated the mechanical stability of the IMSCs. Therefore, this strategy of mixing highly conductive WO2/MoO2@P, N-CNTs can effectively improve the conductivity of the composite material and the mechanical properties of the overall device. Furthermore, this concept can be further extended to the preparation and application of other wearable devices.

Electrochemical study of cerium and iron doped MoO3 nanoparticles showing potential for supercapacitor application

This study presents the synthesis and comprehensive characterization of undoped MoO3 and its cerium (Ce) and iron (Fe) doped counterparts via hydrothermal route, with a 5 % doping concentration. Structural analysis by X-ray diffraction confirmed the formation of MoO3 with successful doping. UV–vis spectroscopy demonstrated tunable optical properties, with band gap energies of 2.3 eV, 2.0 eV, and 2.8 eV for undoped, Ce-doped and Fe-doped MoO3 respectively. Morphological investigation using scanning electron microscopy revealed distinct nanostructures, including nanorods, agglomerated nanoparticles, and pebble-like structures, influenced by doping. Electrochemical characterization through cyclic voltammetry and potentio electrochemical impedance spectroscopy showcased superior charge storage capacity in Fe-doped MoO3, attributed to the largest area under the curve in cyclic voltammograms. Fe-doped MoO3 exhibited lowest resistance as compared to undoped and Ce doped MoO3, suggesting enhanced conductivity. The presence of a Warburg element in all samples indicated diffusion-limited electrochemical processes. The variation of log (scan rate) with log (current) revealed distinct charge transfer mechanisms, with near-unity slopes for doped samples and a slope near 0.5 for undoped MoO3. These findings provide insights into the tunable properties of doped MoO3, offering potential applications in various electrochemical devices.

Fabrication of a Molybdenum Dioxide/Multi-Walled Carbon Nanotubes Nanocomposite as an Anodic Modification Material for High-Performance Microbial Fuel Cells.

A nanocomposite of multi-walled carbon nanotubes (MWCNTs) decorated with molybdenum dioxide (MoO2) nanoparticles is fabricated through the reduction of phosphomolybdic acid hydrate on functionalized MWCNTs in a hydrogen-argon (10%) atmosphere in a tube furnace. The MoO2/MWCNTs composite is proposed as an anodic modification material for microbial fuel cells (MFCs). MWCNTs have outstanding physical and chemical peculiarities, with functionalized MWCNTs having substantially large electroactive areas. In addition, combined with the exceptional properties of MoO2 nanoparticles, the synergistic advantages of functionalized MWCNTs and MoO2 nanoparticles give a MoO2/MWCNTs anode a large electroactive area, excellent electronic conductivity, enhanced extracellular electron transfer capacity, and improved nutrient transfer capability. Finally, the power harvesting of an MFC with the MoO2/MWCNTs anode is improved, with the MFC showing long-term repeatability of voltage and current density outputs. This exploratory research advances the fundamental application of anodic modification to MFCs, simultaneously providing valuable guidance for the use of carbon-based transition metal oxide nanomaterials in high-performance MFCs.

Predicting combustion, performance, and emission characteristics of a compression ignition engine utilising coconut oil methyl ester and MoO3 nanoparticles

The present study used a blend of biofuel and nanoparticles to examine the effectiveness and emission properties of a four-stroke, single-cylinder, direct-injection diesel engine with an injection pressure of 250 bar. The use of MoO3 in biodiesel enhances its environmental sustainability and dependability, making it a promising substitute for traditional diesel fuel. The study emphasises the ecological advantages of using a combination of coconut oil and MoO3 to accomplish the production of renewable energy. MoO3 nanoparticles ultimately function as an oxidation catalyst, enhancing combustion. A study with MoO3 nanoparticles at 50 and 100 ppm concentrations was carried out. Utilising a photo spectrometer, stability was determined. The CI engine demonstrated improved thermal efficiency and reduced Fuel Consumption compared to diesel, both at full load conditions and at 64.5 bar pressure. The performance, combustion, and emission parameters were precisely forecasted using Design Expert, exhibiting a robust connection with the testing results. The Rb values for Brake Specific Fuel Consumption (BSFC), Brake Thermal Efficiency (BTE), Peak Cylinder Pressure (P-CA), Net Heat Release Rate (NHRR), Crankcase Heat Release Rate (CHRR), Carbon Monoxide (CO), Unburned Hydrocarbons (UHC), Nitrogen Oxides (NOX), and Smoke Opacity are 0.997, 0.9998, 0.8898, 0.979, 0.9838, 0.9815, 0.9917, 0.9958, and 0.9261 respectively.

A synergistic combination of 2D MXene and MoO3 nanoparticles for improved gas sensing at room temperature

MXene Ti3C2T x (30% HF-etched, named Ti3C2T x -30) plays a pivotal role in the substantial enhancement of the structural modification of molybdenum trioxide (MoO3). Additionally, as the surface MoO3 molecules come into contact with reducing gas moieties, they actively participate in gas sensing at room temperature. The percentage of Ti3C2T x -30 in the MoO3 matrix was varied at 10%, 20%, and 40%, denoted as MM-10, MM-20, and MM-40, respectively. Structural analysis confirmed the composition of the basic elements and evolution of TiO2 at a higher percentage of Ti3C2T x -30. Spectroscopy analysis showed the interactions between Ti3C2T x -30 and MoO3, showcasing work functions of 6.91 eV, 6.75 eV, and 7.21 eV for MM-10, MM-20, and MM-40, respectively, confirming MM-20 to be an optimum composition. When the samples were exposed to ammonia gas, MM-20 showed a high response (93% for 100 ppm) at room temperature, with a response time of ∼10 s. Compared to bare MoO3, these samples showed ten-fold improvement. The excess electrons on the surface of Ti3C2T x -30 facilitate the formation of O2− species, which also provides stability to the otherwise highly reactive MXene surface. These species actively react with ammonia molecules in the presence of adsorbed MoO3, thereby changing the resistance of the system. This can be a significant step towards imparting high gas sensitivity to metal oxides at room temperature via incorporation of an optimum percentage of optimized Ti3C2T x .

Synergistic adsorption and photocatalytic degradation of tetracycline using a Z-scheme kaolin/g-C3N4/MoO3 nanocomposite: A sustainable approach for water treatment

This research focuses on the synthesis and application of a novel kaolin-supported g-C3N4/MoO3 nanocomposite for the degradation of tetracycline, an important antibiotic contaminant in water systems. The nanocomposite was prepared through a facile and environmentally friendly approach, leveraging the adsorption and photocatalytic properties of kaolin, g-C3N4 and MoO3 nanoparticles, respectively. Comprehensive characterization of the nanocomposite was conducted using techniques such as X-ray diffraction (XRD), scanning electron microscopy (SEM), Fourier-transform infrared spectroscopy (FTIR) and optical spectra. The surface parameters were studied using N2 adsorption-desorption isotherm. The elemental composition was studied using X-ray photoelectron spectroscopy. The efficiency of the developed nanocomposite in tetracycline degradation was evaluated and the results revealed an efficient tetracycline degradation exhibiting the synergistic effects of adsorption and photocatalytic degradation in the removal process. The tetracycline degradation was achieved in 60 min. Kinetic studies and thermodynamic analyses provided insights into the degradation mechanism, suggesting potential applications for the nanocomposite in wastewater treatment. Additionally, the recyclability and stability of the nanocomposite were investigated, demonstrating its potential for sustainable and long-term application in water treatment.

Investigating the potential of ZrO2/MoO3 nanocomposites for efficient hydrogen generation through NaBH4 methanolysis

This work investigates the potential of ZrO2/MoO3 nanocomposites as catalysts for hydrogen production through NaBH4 methanolysis. The samples were prepared by controlled thermal calcination and characterized using various techniques like XRD, FTIR, Raman, SEM, and surface area BET analysis. Rietveld refinements verified the presence of the ZrO2 monoclinic phase with the space group P21/c in all samples and a second orthorhombic MoO3 phase with the space group Pnma. The average crystal size decreased from 44 to 40 nm. FTIR and Raman spectroscopy confirmed the successful preparation of ZrO2/MoO3 nanocomposites. SEM analysis showed ZrO2 particles and MoO3 nanoparticles adhered to the ZrO2 surface, potentially creating a rougher texture. The results confirmed the formation of ZrO2/MoO3 nanocomposites with increasing MoO3 content, leading to an increased surface area of 19–23 m2/g. The catalytic performance evaluation revealed that the sample containing 30 % MoO3 (ZM3) exhibited the highest hydrogen generation rate of 18,451 mL/g. min at 30 °C. The calculated activation energy for ZM3 was 18.78 kJ/mol, suggesting efficient hydrogen generation at moderate temperatures.

Facile green synthesis of Zn doped MoO3 nanoparticles and its photocatalytic and photoluminescence studies

In the field of nanoscience, the use of plant components for the synthesis of nanoparticles (NPs) is currently gaining popularity and has several advantages over physicochemical methods. Murraya koenigii (MK) leaf powder was used as the green fuel in the effective synthesis of the Zinc-doped molybdenum trioxide (Zn-MoO3) NPs by the green combustion method. The green synthesized NPs were characterized using XRD, FTIR, SEM, EDAX, UV–Vis and Photoluminescence (PL) spectroscopy techniques. The XRD pattern revealed the presence of an orthorhombic phase. The Tauc relation was used to calculate the energy band gap value of the samples found to be between 2.9 and 3.1 eV. The prepared NPs emit cyan light. Latent fingerprint analysis has revealed more distinct patterns in the near UV region (365 nm) and is useful in forensic investigations. The Rose Bengal (RB) dye degradation experiments are carried out under UV light exposure. Zn-MoO3 NPs have greater degradation efficiency than pure MoO3 NPs. Up to 99 % dye degradation is achieved in 150 min. After 3 photocatalysis cycles, the recycling test detects only an 8% decrease in photocatalyst efficiency. The obtained results proved that Zn-doped MoO3 NPs are the most suitable photocatalyst for RB degradation.

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.

Bridging the gap between metallic MoO2 and ZnIn2S4 for enhanced photocatalytic H2 production

Noble metal-free cocatalysts have shown unprecedented potential in enhancing photocatalytic H2 evolution. However, it remains challenging to accelerate the carrier transfer rate by circuiting the substantial Schottky barrier between the metallic cocatalyst and the semiconductor. Herein, an in-situ carbonization strategy is used to accurately anchor MoO2 nanoparticles onto the surface of conductive carbon rods (MoO2/C), which serves as an efficient and stable metallic cocatalyst for ZnIn2S4 towards photocatalytic H2 evolution. The in-site derived carbon skeleton not only prevents the agglomeration of MoO2 nanoparticles thus enriching the active sites for H2 evolution, but also acts as conductor of photogenerated electrons to accelerate electron transfer. In addition, the formed Mo-S bonds at the interface provide additional electron transport channels for hierarchical core–shell MoO2/C@ZnIn2S4 (MO/C@ZIS) heterojunction. It is worth noting that the H2 evolution activity of the optimized MO/C@ZIS sample (2357 μmol·h−1·g−1) is 8.7 times higher than pure ZnIn2S4 (271 μmol·h−1·g−1), and also surpasses the activity of optimized Pt-modified ZnIn2S4 (2123 μmol·h−1·g−1). This work casts a new paradigm for the rational engineering of heterointerface between metallic cocatalysts and semiconductors towards fast electron transport and enhanced photocatalytic performance.