Rhodium Oxide Research Articles

(Invited) All-Solid-State Z-Scheme Overall Water-Splitting Photocatalysts for Effective Utilization of Solar Energy

Since Fujishima and Honda reported photoelectrochemical water splitting using a TiO2 electrode in 1972 [1], solar hydrogen (H2) from water using a photocatalyst has attracted attention as a clean energy resource. Most recent research has been focusing on the visible-light sensitization of catalysts to effectively utilize solar energy. Our group has investigated water-splitting photocatalysts that are able to utilize the whole range of visible light and even infrared light on the basis of material designs and mechanistic approaches. We successfully created a solid-state hetero-junction photocatalyst, following a conventional well-known Z-scheme mechanism [2], but the present photocatalyst did not require any chemicals as a redox mediator. The solid-state hetero-junction photocatalyst is silver (Ag) inserted zinc rhodium oxide (ZnRh2O4 (ZRO), bandgap energy (E g) of 1.2 eV) and bismuth vanadate (Bi4V2O11 (BVO), E g of 1.7 eV), abbreviated to ZRO/Ag/BVO, where Ag, ZRO, and BVO act as an electron mediator, H2-evolution photocatalyst, and oxygen (O2)-evolution photocatalyst, respectively [3,4]. Overall water splitting, liberating H2 and O2 simultaneously from pure water at a stoichiometric ratio 2 to 1, was accomplished using ZRO/Ag/BVO irradiated with red light at wavelengths of up to 740 nm. This system functioned via the inserted Ag which could transfer photoexcited electrons from the conduction band (CB) of BVO to the valence band (VB) of ZRO. The photoexcited electrons in the CB of ZRO and photogenerated holes in the VB of BVO can effectively reduce and oxidize water, respectively, producing H2 and O2 at a molar ratio of 2 to 1.In place of BVO, silver vanadium oxide (Ag2V4O11 (AVO), E g of 1.4 eV) was utilized to directly connect to ZRO, forming ZRO/BVO. ZRO/BVO accomplished overall pure-water splitting under irradiation with near-infrared light at wavelengths of up to 910 nm. The key point without an electron mediator is that the CB potential of AVO is almost the same as the VB top potential of ZRO [5]. Thus, photoexcited electrons transfer smoothly from the CB of AVO to the VB of ZRO.Notably, both ZRO/Ag/BVO and ZRO/AVO systems did not include a cocatalyst, which is inevitably required for the water splitting reaction due to the increase in the lifetime of electron-and-hole pairs and storing either electrons or holes. Thus, to enhance the water splitting activity, we tried to load a cocatalyst, platinum (Pt), Ag or copper (Cu), selectively onto the H2-evolution photocatalyst, ZRO, in ZRO/Ag/BVO to enhance the photosensitivity of this system. The loading of Pt, Ag, or Cu was performed by a photo-deposition method under light irradiation at wavelength longer than 850 nm. Under the irradiated light condition, only ZRO was photo-excited because the energy of irradiated light was higher than the E g of ZRO (1.2 eV) but smaller than that of BVO (1.7 eV). Due to the specific photoexcitation of ZRO, Pt, Ag, or Cu was expected to be only photo-deposited onto this material, generating Pt/ZRO/Ag/BVO, Ag/ZRO/Ag/BVO, or Cu/ZRO/Ag/BVO. The deposition of Pt, Ag, or Cu 3-fold enhanced the H2 and O2 evolution rates compared to those of bare ZRO/Ag/BVO, demonstrating that Pt, Ag and Cu functioned as cocatalysts for the overall water-splitting reaction [6,7]. In addition, we discuss on the selective loading of a cocatalyst, cobalt oxide (CoOx), onto the O2-evolution photocatalyst, BVO, in ZRO/Ag/BVO and co-loading of Cu and CoOx on ZRO and BVO, respectively, at the conference.This work was performed by Assoc. Prof. T. Takashima, Mr. M Yoda, and Mr. J. Osaki. I am deeply grateful to JSPS KAKENHI (Grant-in-Aid for Scientific Research) (B), Grant Number JP21H02043 for its financial support.

Schottky Interface Enabled Electrospun Rhodium Oxide Doped Gold for Both pH Sensing and Glucose Measurements in Neutral Buffer and Human Serum.

This study has focused on adjusting sensing environment from basic to neutral pH and improve sensing performance by doping electrodeposited gold (Au) with metal oxide for nonenzymatic glucose measurements in forming a Schottky interface for superior glucose sensing with detailed analysis for the sensing mechanism. The prepared sensor also holds the ability to measure pH with the identical electrospun metal oxide-electrodeposited Au, which composed a dual sensor (glucose and pH sensor) through applying chronoamperometry and open circuit potential methods. The rhodium oxide nanocoral structure was fabricated with an electrospinning precursor solution, followed by a calcination process, and it was mixed with electrodeposited nanocoral gold to form the Schottky interface by constructing a p-n type heterogeneous junction for improved sensitivity in glucose detection. The prepared materials were characterized by X-ray powder diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), and X-ray photoelectron spectrometry (XPS), etc. The prepared materials were used for both pH responsive testing and amperometric glucose measurements. The rhodium oxide nanocoral doped gold demonstrated a sensitivity of 3.52 μA mM-1 cm-2 and limit of detection of 20 μM with linear range up to 3 mM glucose concentration compared to solely electrodeposited gold for a sensitivity of 0.46 μA mM-1 cm-2 and a limit of detection of 450 μM. The Mott-Schottky method was used for the analysis of an electron transfer process from noble metal to metal oxide to electrolyte in demonstrating the improved sensitivity at neutral pH for glucose measurements due to the Schottky barrier adjustment mechanism at an applied flat band potential of 0.3 V. This work opens a new venue in illustrating the metal oxide/metal materials in the glucose neutral response mechanism. In the end, human serum samples were tested against current commercial glucose meter to certify the accuracy of the proposed sensor.

Probing the geometric and electronic structure of rhodium oxide clusters (RhO)n− (n = 2–4) by anion photoelectron spectroscopy and theoretical calculations

The cluster configurations of (RhO)n− (n = 2–4) have been examined using photoelectron (PE) velocity-map imaging combined with density functional theory calculations. The PE spectra have provided the anion detachment energies (ADEs) information of three ground states, determined to be 2.40, 2.86, and 2.94 eV for n = 2–4, respectively. The geometric structures have been identified by comparing the density of states (DOS) spectra of several low-lying isomers with the PE spectra. The three cluster configurations consist of a Rhn (n = 2–4) core with isolated O atoms bonded to the core, exhibiting planar or quasi-planar geometries. The analysis of magnetic moments and spin densities indicated that the most stable three anions have high spin multiplicities of 4, 5, and 4 for n = 2–4, respectively, with the unpaired electrons delocalized on each of the Rh and O atoms.

Catalytic oxidation of carbon monoxide at low temperature using AuRh/TiO2 bimetallic catalysts: Effect of the synthesis method

AuRh nanoparticles supported on TiO2 P25 were synthesized by two sequential deposition methods: sequential deposition-precipitation with urea (DPU) and impregnation (IMP)-DPU. Segregated nanoparticles (RhcoreAushell ball-cup-type, and Janus-type arrangements) were observed in gold-rhodium bimetallic catalysts, but mainly ball-cup-type and Janus-type nanoparticles were found on catalysts prepared by IMP-DPU. XPS analysis of gold-rhodium bimetallic catalysts, before and after reaction allowed concluding that gold-rhodium interaction on metallic state was an important factor to avoid the oxidation of rhodium during CO oxidation. However, this effect of stabilization of the rhodium metallic phase by gold does not fully explain the promoting effect observed for some bimetallic catalysts on CO oxidation. Some structural aspects such as the atomic arrangement of the bimetallic nanoparticles and the type of active sites, determined by DRIFTS-CO, were also considered. TPR and UV–visible DR spectroscopy characterizations also showed differences in the gold-rhodium interactions.

Amorphous RhOx decorated black indium oxide for rapid and flexible NO2 detection at room temperature

This paper focuses on the preparation and characterization of a composite material made from rhodium oxide amorphous-decorated black indium oxide (RhOx/B-In2O3) for use in MEMS gas sensors. The sensors were utilized for the detection of NO2 gas at room temperature, and the results demonstrate that the RhOx/B-In2O3 sensor exhibits excellent gas selectivity, high response, and extremely short response/recovery times (8 s/17 s) to 5 ppm NO2 gas at room temperature. Additionally, a flexible NO2 gas sensor based on the optimized RhOx/B-In2O3 composite was fabricated to expand its application. One of the unique aspects of the RhOx/B-In2O3 material is the existence of defects, which allows for greater adsorption of NO2 gas. This feature contributes to the increased gas selectivity seen in the B-In2O3 material as compared with common In2O3. The chemical sensitization and electron-rich properties of amorphous RhOx further enhance the gas-sensing performance of the material by reducing the reaction activation energy and increasing surface-adsorbed oxygen. Overall, the results demonstrate the potential of the RhOx/B-In2O3 composite material for use in advanced gas-sensing technologies.

Probing the geometric and electronic structures of the transition metal oxides RhOn–1/0 (n = 1–4) clusters

The photoelectron spectroscopies of RhOn– (n = 1–2) were obtained via using the photoelectron velocity-map imaging (PE-VMI) approach. The experimental values of the adiabatic detachment energy (ADE) and vertical detachment energy (VDE) for RhO– were reported to be 1.58 ± 0.02 eV. The experimental AED and VDE values of RhO2– were reported to be 2.70 ± 0.02 eV and 2.79 ± 0.02 eV, respectively. The vibrational frequencies of RhO– and RhO2– measured from photoelectron spectra (PES) were 817(76) cm−1 and 932(55) cm−1, respectively. Based on the density functional theory (DFT), the RhOn–1/0 (n = 1–4) clusters were investigated. The optimized configurations of corresponding ground states and low-lying clusters were discovered. Meanwhile, the simulated photoelectron spectroscopy (PES) of RhOn– (n = 1–4) and the theoretical ADE and VDE values of RhOn– (n = 1–4) clusters were unveiled to assist future experimental studies of Rhodium oxide clusters. Moreover, the associated molecular orbitals (MOs), natural population analysis (NPA) and bond order analysis have been utilized to investigate the chemical bonding in these groups.

Enhanced N2O decomposition on Rh/ZrO2 catalysts through the promotional effect of palladium

Supported rhodium oxide (RhOx) catalysts have emerged as highly promising for effectively catalytic decomposition of N2O, hence contributing to the mitigation of greenhouse gas emission and combating global warming. Supported RhOx catalysts outperform catalysts employing zeolites and composite metal oxides even under challenging conditions involving O2, H2O, and CO2. This study explores the augmentation of Rh/ZrO2 (RhOx supported on monoclinic ZrO2) catalyst efficiency through the addition of palladium (Pd) to yield RhPd/ZrO2. The augmented catalyst demonstrates notable improvements in N2O decomposition under both N2O-only and more realistic conditions (N2O + O2 + H2O + CO2). Various techniques, including high-angle annular dark-field scanning transmission electron microscopy and X-ray absorption spectroscopy, were employed to investigate the structural characteristics of Rh and Pd species on ZrO2. Kinetic studies further delved into the promotional effect, revealing that the introduction of Pd enhanced the catalytic activity of RhOx catalysts by augmenting their thermal reduction capability. This enhancement proved beneficial in facilitating the efficient progression of the rate-determining step for N2O catalytic decomposition, namely the thermal reduction of the catalyst to produce gaseous O2, particularly at low temperatures. These results highlight the potential of Pd-mediated improvements in Rh/ZrO2 catalysts for sustainable and efficient N2O decomposition.

Bifunctional heterogeneous catalyst: A sustainable route for cyclic acetals synthesis through tandem hydroformylation-acetalization reaction

A novel sustainable approach for the synthesis of 2-ethyl 1,3 dioxolane and various short to long-chain or aromatic cyclic acetals through a tandem hydroformylation-acetalization reaction using Rh oxide nanoparticle supported on zirconium phosphate has been established. The Rh oxide nanoparticle supported on zirconium phosphate was synthesized and characterized by various physicochemical methods. The SEM and TEM analysis revealed the average particle size of rhodium oxide was found to be ∼7.56 nm in 2%Rh@ZrP catalyst. Furthermore, the synthesized catalyst was employed to carry out a tandem hydroformylation reaction in a green solvent (ethylene glycol). Experimental results demonstrated that 2 wt.% of Rhodium on zirconium phosphate efficiently activated olefins, leading to the selective formation of cyclic acetals (60–99%) at 80°C for 6 h. In this cascade reaction, significant selectivity towards the desired product, linear cyclic acetals was observed for styrenes. This can be attributed to highly dispersed Rh oxide nanoparticles and plentiful acidic sites on the zirconium phosphate supports, which played a crucial role in tandem hydroformylation and acetalization reactions. The catalyst exhibited the ability to be reused three times without losing significant catalytic activity or selectivity. This is the first report on the synthesis of a fuel additive and other cyclic acetals via a tandem hydroformylation-acetalization reaction using heterogeneous catalysts.

Hydrogenation of functionalised pyridines with a rhodium oxide catalyst under mild conditions.

Piperidines are one of the most widely used building blocks in the synthesis of pharmaceutical and agrochemical compounds. The hydrogenation of pyridines is a convenient method to synthesise such compounds as it only requires reactant, catalyst, and a hydrogen source. However, this reaction still remains difficult for the reduction of functionalised and multi-substituted pyridines. Here we report the use of a stable, commercially available rhodium compound, Rh2O3, for the reduction of various unprotected pyridines. The reaction only requires mild conditions, and the substrate scope is broad, making it practically useful.

Electrocatalytic Activities of High-Entropy Oxides for the Oxygen Evolution Reaction

Electrocatalytic water-splitting hydrogen generation consists of the cathodic hydrogen evolution reaction (HER) and the anodic oxygen evolution reaction (OER), where the four-electron-relevant OER is the rate-determining step. So far, there have been many efforts to substitute for the highly expensive noble-metal electrocatalysts (platinum, ruthenium or rhodium oxides, etc.). Transition-metal oxides based on Co, Ni, Mn, and V have been suggested as such alternatives, due to their low cost, high efficiency, and high stability. Recently, since the compositional diversity can provide a new breakthrough in that area, a high-entropy oxide (HEO) with five transition-metal cations has been suggested as a promising electrocatalyst toward the OER. In our studies, two kinds of HEOs were prepared and their OER activities were investigated. To begin with, for the (Mg0.2Fe0.2Co0.2Ni0.2Cu0.2)O, the effect of constituent cations on the OER activity was unveiled. Furthermore, a core cation driving the high OER activity was found. For it, the medium-entropy oxides (MEOs) with four cations are prepared by subtracting each cation (Mg, Fe, Co, Ni, or Cu) from the HEO, exhibiting homogeneous morphology, equiatomic composition, and single-phase rocksalt structure. As a result, it is found that the highest concentration of Co3+ in the MEO (w/o Cu) leads to the best OER activity, and thus Co3+ is the core ion driving the high OER activity. Furthermore, it is regarded that Cu2+ ions prevent the conversion of Co or Fe cations from 2+ to 3+ in the HEO and MEOs. Accordingly, maximizing the concentration of Co3+ within electrocatalysts is suggested as an effective design strategy for the high-efficiency electrocatalysts based on high or medium entropy materials. Secondly, the relationship between structure and OER activity was elucidated for the (Mg0.2Fe0.2Co0.2Zn0.2Cu0.2)O with a temperature-dependent rocksalt-to-spinel transition.

Nitrogen contained rhodium nanosheet catalysts for efficient hydrazine oxidation reaction

The hydrazine oxidation reaction (HzOR) has been considered as a more energy-efficient alternative to the oxygen evolution reaction in water electrolysis. To design efficient electrocatalysts for HzOR, precise engineering of materials is required to increase active sites and build electronic structures. Herein, nitrogen contained face-centered cubic rhodium (N-fcc-Rh) nanosheets are prepared by directly annealing metastable trigonal rhodium oxide precursor in the ammonia atmosphere. Benefiting from the abundant active sites and unique electronic structure, the optimal N-fcc-Rh-300 electrocatalyst achieves an ultra-low working potential of − 81 mV (vs. RHE) at 10 mA cm−2 in 1.0 M KOH/0.5 M N2H4. Density functional theory calculations suggest the N element in the N-fcc-Rh electrocatalyst enables to the reduction of the formation energy of the potential-determining step from *NH2NH2 to *NHNH2 for the HzOR process. This work reveals a new strategy to prepare advanced metal electrocatalysts for various electrochemical applications.

Emergent Intrinsic Ferromagnetism in Two-Dimensional Trigonal Rhodium Oxide.

Two-dimensional (2D) van der Waals single crystals with long-range magnetic order are the precondition and urgent task for developing a 2D spintronics device. In contrast to graphene and transition metal dichalcogenides, the study of 2D single-crystal metal oxides with intrinsic ferromagnetic properties remains a huge challenge. Here, we report a large-size trigonal single-crystal rhodium oxide (SC-Tri-RhO2), with crystal parameters of a = b = 3.074 Å, c = 6.116 Å, and a space group of P3̅m1 (164), exhibiting strong ferromagnetism (FM) at a rather high temperature. Furthermore, theoretical calculations suggest that the ferromagnetism in SC-Tri-RhO2 originates from spin splitting near the Fermi level, and the total magnetic moment is contributed mainly by the Rh atom.

A Red Light-Inducible Copper-Photodeposited All-Solid-State Z-Scheme Photocatalyst for Carbon Dioxide Reduction to Methane Using Water as an Electron Donor

We selectively loaded various amounts of copper (Cu) as a cocatalyst for the reduction reaction onto zinc rhodium oxide (ZnRh2O4 (ZRO)) in a heterojunction photocatalyst and silver (Ag)-inserted ZRO and bismuth vanadium oxide (Bi4V2O11 (BVO)) solid-state photocatalyst (ZRO/Ag/BVO (ZAB)) to form Cu/ZAB. The amount of deposited Cu was controlled by the photodeposition time to generate Cu/ZAB with up to 0.14 wt % Cu cocatalyst vs ZAB. All the prepared Cu/ZAB samples accomplished overall water splitting under red light irradiation at a wavelength of 700 nm, enhancing the stoichiometric evolutions of hydrogen and oxygen from water compared with bare ZAB. Moreover, the apparent quantum efficiency increased up to 0.13 wt % Cu cocatalyst, which thereafter tended to decrease. The optimized Cu/ZAB photocatalyst was confirmed to reduce carbon dioxide (CO2) to methane using water as an electron donor and proton source under irradiation with visible light at a wavelength of 700 nm, which is, to our knowledge, the longest wavelength reported to date for CO2 reduction.

Factors determining rhodium solubilization efficiency in molten K2CO3–K2O–B2O3–Al2O3 medium

Dilute-acid-soluble, complex rhodium oxides were generated in a molten K2CO3–K2O–B2O3–Al2O3 medium, and factors affecting their generation efficiency were investigated. Surface observation revealed that planar-shaped materials (the insoluble rhodium compounds) were covered by fine particles (the acid-soluble rhodium compounds) in the heat-treated rhodium. The fine particles contained Rh, K, Al, B, Ca, Si, and O. In contrast, the main components of the insoluble rhodium compounds were Rh, K, Al, Si, and O. Therefore, an efficient reaction of B and Ca with rhodium is an essential factor in solubilizing rhodium. The oxidation state of rhodium in the acid-soluble compounds was higher than that of the insoluble rhodium compounds, implying that efficient rhodium oxidation is another factor for rhodium solubilization. When air was supplied while synthesizing the rhodium compounds to enhance the oxidizing condition, rhodium extraction from the obtained heat-treated products increased to 74%.

In-situ adaptive evolution of rhodium oxide clusters into single atoms via mobile rhodium-adsorbate intermediates

It is a common phenomenon for supported metal catalysts to undergo thermally-induced or adsorbate-induced reconstruction. Great efforts have been devoted to making these reconstruction adaptive to the reaction environment instead of deactivation. Herein, we reported the evolution of initially inactive RhOx clusters on Al2O3 into the formation of catalytically active oxygen vacancies and Rh single atoms via mobile Rh-CO intermediates during hydroformylation of propene. The activated catalyst exhibited a high specific activity of 3.0 × 104 mol molRh–1 h–1 towards hydroformylation reaction. Mechanistic studies revealed the evolution paths. Specially, RhOx clusters were reduced by CO to form oxygen vacancy where the surrounding unsaturated Rh atoms enabled the chemisorption of CO*. Rh atoms that were ejected from RhOx clusters diffused on Al2O3 supports to generate Rh single atom via the formation of carbonyl or geminal dicarbonyl species. Meanwhile, the Rh atoms on clusters were also leached to the solution by the adsorbed CO molecules, followed by partial re-adsorption on the support. This work not only offers an efficient catalyst for propene hydroformylation, but also advances the understandings of dynamic evolution of catalysts.

Lattice stain dominated hydrazine oxidation reaction in single-metal-element nanosheet

Electrocatalytic water decomposition is an essential pathway for large-scale preparation of high-purity hydrogen, while the conventional oxygen evolution reaction (OER) with a kinetically sluggish four-electron process becomes a huge challenge for its further application. Hydrazine oxidation reaction (HzOR) is considered an effective strategy to replace the sluggish OER process, attributed to its lower thermodynamic oxidation potential. Here, porous rhodium nanosheets (Rh-NSs) with tunable lattice strain are successfully obtained by directly annealing metastable trigonal rhodium oxide (Tri-RhO2) in a hydrogen atmosphere. More importantly, ligand and synergetic effects can be effectively avoided in a single-metal-element system, providing an ideal model electrocatalyst for understanding the correlation between reactivity and lattice strain. The electrochemical results show that the optimal Rh-NSs-300 (the Tri-RhO2 precursor is annealed at 300 °C) may deliver ultralow working potential (vs. RHE) of −103 mV at the current density of 10 mA cm−2 with a Tafel slope of 15.4 mV dec-1 for HzOR. In addition, the working potential (vs. RHE) of Rh-NSs-300 only drops 35 mV after the 72 h test by chronopotentiometry method at the constant current density of 10 mA cm−2. Density functional theory (DFT) calculations indicate that HzOR can more easily occur on Rh-NSs with tunable compressive strain than pure Rh.

Stability and Activity of Rhodium Promoted Nickel-Based Catalysts in Dry Reforming of Methane.

The rhodium oxide (Rh2O3) doping effect on the activity and stability of nickel catalysts supported over yttria-stabilized zirconia was examined in dry reforming of methane (DRM) by using a tubular reactor, operated at 800 °C. The catalysts were characterized by using several techniques including nitrogen physisorption, X-ray diffraction, transmission electron microscopy, H2-temperature programmed reduction, CO2-temperature programmed Desorption, and temperature gravimetric analysis (TGA). The morphology of Ni-YZr was not affected by the addition of Rh2O3. However, it facilitated the activation of the catalysts and reduced the catalyst's surface basicity. The addition of 4.0 wt.% Rh2O3 gave the optimum conversions of CH4 and CO2 of ~89% and ~92%, respectively. Furthermore, the incorporation of Rh2O3, in the range of 0.0-4.0 wt.% loading, enhanced DRM and decreased the impact of reverse water gas shift, as inferred by the thermodynamics analysis. TGA revealed that the addition of Rh2O3 diminished the carbon formation on the spent catalysts, and hence, boosted the stability, owing to the potential of rhodium for carbon oxidation through gasification reactions. The 4.0 wt.% Rh2O3 loading gave a 12.5% weight loss of carbon. The TEM images displayed filamentous carbon, confirming the TGA results.

Near-infrared light-inducible Z-scheme overall water-splitting photocatalyst without an electron mediator.

We facilely prepared a solid-state heterojunction photocatalyst in which silver vanadium oxide (Ag2V4O11) and zinc rhodium oxide (ZnRh2O4) as oxygen and hydrogen evolution photocatalysts, respectively, were directly connected to generate Ag2V4O11/ZnRh2O4. Ag2V4O11/ZnRh2O4 photocatalyzed overall pure-water splitting without any electron mediator under irradiation with near-infrared light at wavelengths of up to 910 nm. The key points are that the conduction bottom potential of Ag2V4O11 is almost the same as the valence band top potential of ZnRh2O4, and that the bandgaps of Ag2V4O11 and ZnRh2O4 are 1.4 and 1.2 eV, respectively.

Comparative Performance and Emissions of CI Engine Fuelled with Diesel and Blends of Mosambi Peel Pyro Oil, Methanol and Nano Rh2O3 with Diesel

This research article presents a comparative experimental study on the performance, exhaust emission and combustion characteristics of a CI engine fuelled with neat diesel and with three kinds of blends viz. MD10 (neat diesel with 10% mosambi peel pyro oil), MDM10 (neat diesel with 10% mosambi peel pyro oil and 10% methanol), MD10+Rh2O3 (neat diesel with 10% mosambi peel pyro oil and nano rhodium oxide fuel additive). The experiments were conducted on a direct injection single-cylinder water-cooled four-stroke diesel engine operated at a constant engine speed of 1500 rpm and under varied brake power conditions. The results showed that MD10+Rh2O3 outperformed the rest in terms of all the performance, emission and combustion characteristics. MD10+Rh2O3 was found to have achieved, 5% higher brake thermal efficiency, 18.5% reduced SFC and 8% reduced exhaust gas temperatures respectively. This fuel has also achieved 10.5%, 5.5%, 9.45%, 11% marginal drop in noxious pollutants such as CO (Carbon Monoxide), unburnt HC (Hydrocarbons), NOx and smoke respectively. Cylinder peak pressures, heat release rate, ignition delay and combustion duration of MD10+ Rh2O3 are recorded to be considerably improved. Thus, using the nanoparticle added mosambi peels pyro oil (NMPPO) blended with diesel as an alternative fuel could impart an eco-friendly, efficient and improved engine operation.

Progress in research on rhodium (III) oxide or rhodium sesquioxide (Rh2O3) and rhodium (IV) oxide (RhO2) nanoparticles in cancer prevention, prognosis, diagnosis, imaging, screening, treatment and management under synchrotron and synchrocyclotron rad

In the current research, progress in research on Rhodium (III) Oxide or Rhodium Sesquioxide (Rh2O3) and Rhodium (IV) Oxide (RhO2) nanoparticles in cancer prevention, prognosis, diagnosis, imaging, screening, treatment and management under synchrotron and synchrocyclotron radiations. is investigated. The calculation of thickness and optical constants of Rhodium (III) Oxide or Rhodium Sesquioxide (Rh2O3) and Rhodium (IV) Oxide (RhO2) progress in research on Rhodium (III) Oxide or Rhodium Sesquioxide (Rh2O3) and Rhodium (IV) Oxide (RhO2) nanoparticles in cancer prevention, prognosis, diagnosis, imaging, screening, treatment and management under synchrotron and synchrocyclotron radiations produced using sol–gel method over glassy medium through a single reflection spectrum is presented. To obtain an appropriate fit for reflection spectrum, the classic Drude–Lorentz model for parametric di–electric function is used. The best fitting parameters are determined to simulate the reflection spectrum using Lovenberg–Marquardt optimization method. The simulated reflectivity from the derived optical constants and thickness are in good agreement with experimental results.
 Progress in research on Rhodium (III) Oxide or Rhodium Sesquioxide (Rh2O3) and Rhodium (IV) Oxide (RhO2) nanoparticles in cancer prevention, prognosis, diagnosis, imaging, screening, treatment and management under synchrotron and synchrocyclotron radiations.