Ternary Catalyst Research Articles

Zn/La/Mg 삼원계 금속 산화물 촉매를 이용한 글리시돌 합성

본 연구에서는 바이오디젤의 부산물인 글리세롤로부터 생성된 글리세롤 카보네이트의 고부가가치화를 위해 글리세롤 카보네이트의 탈카르복시화(Decarboxylation)를 통하여 글리시돌을 제조하였다. Zn, La, Mg의 삼원계 촉매를 함침법으로 제조하였고, 제조된 촉매를 이용하여 글리세롤카보네이트의 탈카르복시화 반응을 통해 글리시돌 합성을 진행하여 담지 금속 종류에 따른 촉매 특성분석과 활성의 상관관계에 대하여 연구하였다. 제조된 촉매는 X-ray diffraction (XRD), N₂ adsorption-desorption isotherm, Field emission-scanning electron microscopy (FE-SEM) 및 NH₃/CO₂-temperature programmed desorption (TPD)를 이용하여 물리 · 화학적 특성 분석을 진행했으며, 글리세롤 카보네이트의 전화율 및 생성된 글리시돌 수율을 확인하여 촉매 특성과의 관계를 확인하였다. Zn/La 이원계 촉매에 Mg이 담지된 경우 산 및 염기점의 비율이 1.85로 가장 높게 나타났고, 그에 따라 88.06%의 글리시돌수율로 가장 높은 촉매 활성을 나타내었다. 본 실험 결과를 통하여 글리시돌의 합성에서 촉매 표면의 산 및 염기점의 높은 비율이 중요하게 작용된다는 것을 알 수 있었다.

Photocatalytic performance of binary and ternary Pt–Cu2O–BiVO4 catalysts under visible-light irradiation

Various Pt–Cu2O–BiVO4 ternary and binary hybrid composite catalysts were synthesized using in-situ methods. Cuprous oxide and platinum were obtained by chemical reduction of copper sulfate and hexachloroplatinic acid, respectively, while BiVO4 was synthetized by ultrasonic spray pyrolysis. All the synthesis routes allowed the formation of ternary and binary catalysts without the presence of impurities. The materials were structurally characterized using X-ray diffraction, morphologically by scanning electron microscopy and transmission electron microscopy, optically with UV–vis diffuse reflectance spectroscopy, and photocatalytically during the degradation of methyl orange (MO) under visible-light irradiation. TEM images confirmed the formation of heterojunctions and the deposition of metallic particles on the semiconductor surfaces. A similar performance was displayed by Cu2O/Pt–BiVO4, Pt-(Cu2O/BiVO4), Pt–BiVO4 and Cu2O/BiVO4 photocatalysts showing ca. 90% of MO degradation, which could indicate a competitive mechanism between Pt and Cu2O as co-catalysts of ternary composites. A significant content of Cu2O in the photocatalysts generated an important dye absorption, like in Cu2O and Pt–Cu2O catalysts. Cu2O/Pt–BiVO4 exhibited the highest production of hydroxyl radicals, indicating the important role of Pt deposition to increase the photocatalytic performance of the semiconductors via the electron sink effect.

Synthesis of ternary magnetic nanoparticles for enhanced catalytic conversion of biomass-derived methyl levulinate into γ-valerolactone

Conversion of levulinic acid and its esters into versatile γ-valerolactone (GVL) is a pivotal and challenging step in biorefineries, limited by high catalyst cost, the use of hydrogen atmosphere, or tedious catalyst preparation and recycling process. Here we have successfully synthesized a ternary magnetic nanoparticle catalyst (Al2O3-ZrO2/Fe3O4(5)), over which biomass-derived methyl levulinate (ML) can be quantitively converted to GVL with an extremely high selectivity of > 99% and yield of ~98% in the absence of molecular hydrogen. Al2O3-ZrO2/Fe3O4(5) incorporates simultaneously inexpensive alumina and zirconia onto magnetite support by a facile coprecipitation method, giving rise to a core-shell structure, well-distributed acid-base sites, and strong magnetism, as evidenced by the X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), transmission electron microscopy (TEM), high-angle annular dark-field scanning-TEM (HAADF-STEM), SEM-energy dispersive X-ray spectroscopy (SEM-EDX), temperature-programmed desorption of ammonia (NH3-TPD), temperature-programmed desorption of carbon dioxide (CO2-TPD), pyridine-adsorption infrared spectra (Py-IR), and vibrating sample magnetometry (VSM). Such characteristics enable it to be highly active and easily recycled by a magnet for at least five cycles with a slight loss of its catalytic activity, avoiding a time-consuming and energy-intensive reactivation process. It is found that there was a synergistic effect among the metal oxides, and the high efficiency and selectivity originating from such synergism are evidenced by kinetic studies. Furthermore, a reaction mechanism regarding the hydrogenation of ML to GVL is proposed by these findings, coupled with gas chromatography-mass spectrometry (GC-MS) analysis. Accordingly, this readily synthesized and recovered magnetic nanocatalyst for conversion of biomass-derived ML into GVL can provide an eco-friendly and safe way for biomass valorization.

Visible-light-driven ZnO/ZnS/MnO2 ternary nanocomposite catalyst: synthesis, characterization and photocatalytic degradation of methylene blue

Visible-light-driven ZnO/ZnS/MnO2 ternary nanocomposite catalyst: synthesis, characterization and photocatalytic degradation of methylene blue

Polymer-based immobilized Fe2O3–TiO2/PVP catalyst preparation method and the degradation of triclosan in treated greywater effluent by solar photocatalysis

The present study involves a novel protocol to develop a ternary composite catalyst for an effective post-treatment technique for greywater. The ternary film of Fe2O3–TiO2/polyvinyl pyrrolidine (PVP) is coated on a glass tube using spray coating with annealing at 320 °C. The structure, thermal, microstructure, and surface properties of the coated film are characterized by X-ray diffraction (XRD), Fourier Transform Infrared Spectroscopy (FTIR), Field Emission Scanning Electron Microscopy (FESEM), and Thermo Gravimetric Analysis (TGA). The scratch hardness of photocatalysts at different Fe2O3/TiO2 compositions is investigated based on the width measurement of scratch using FESEM analysis. Results show that at an optimum coating of 5% of Fe2O3/TiO2 composition catalytic film, the maximum scratch hardness (7.984 GPa) is obtained. Also, the photocatalyst has the highest cohesive bond strength and wearing resistance. The degradation of triclosan (TCS) in treated greywater, discharged from the anaerobic-aerobic treatment system, is investigated at a lab-scale using a solar photocatalytic reactor. The response surface analysis has been performed from the different sets of experimental trials for various optimal parameters. It is observed that the TCS degradation efficiency of 83.27% has resulted under optimum conditions.

Design and fabrication of C–Mn0.5Cd0.5S/Cu3P ternary heterojunction catalyst for photocatalytic hydrogen evolution

Photocatalytic hydrogen evolution from water splitting is a promising strategy to solve the energy demand of human beings. Here, we first designed a C–Mn0.5Cd0.5S/Cu3P ternary heterojunction catalyst for photocatalytic hydrogen production. The results show that the combination of C and Cu3P can effectively improve the photocatalytic activity of Mn0.5Cd0.5S. C–Mn0.5Cd0.5S loading with 5 wt% Cu3P exhibits the highest hydrogen evolution rate (44.1 mmol g−1 h−1), which is 3.2 and 2.8 times higher than that of pure Mn0.5Cd0.5S (13.7 mmol g−1 h−1) and Mn0.5Cd0.5S/3 wt%Pt (15.6 mmol g−1 h−1), respectively. In addition, it shows a high hydrogen evolution rate (19.6 mmol g−1 h−1) under visible light (≥420 nm) irritation and the apparent quantum efficiency (AQE) is detected to be 3.2% at 420 nm. The enhanced photocatalytic activity can be attributed to the good conductivity of C and the formation of p-n heterojunction, which is beneficial for light harvesting and the separation and transportation of charge carriers. Besides, a possible mechanism is proposed. This work provides an effective way to improve the photocatalytic activity of Mn0.5Cd0.5S by using non noble metal co-catalysts.

MoS2 and g-C3N4 nanosheet co-modified Bi2WO6 ternary heterostructure catalysts coupling with H2O2 for improved visible photocatalytic activity

MoS2 and g-C3N4 nanosheet co-modified Bi2WO6 ternary heterostructure catalyst (g-C3N4/MoS2/Bi2WO6) has been synthesized through the hydrothermal and ultrasound method and applied for tetracycline (TC) degradation in synergy with H2O2 under visible light irradiation. The CN/MS/BWO catalysts were analyzed by XRD, SEM, HRTEM, PL, FI-IR, XPS and UV–vis DRS. The optimal 3CN/0.5MS/BWO catalyst can degrade 90% of TC for 60 min under visible light with H2O2 (2 mL/L), being 30% higher than that of pure Bi2WO6. Recycling experiments showed that the photocatalysts maintained outstanding stability after five-time recycles. The improved photocatalytic ability of the CN/MS/BWO heterostructure was owing to the increased visible-light absorption and photogenerated electron-hole pairs separation rate. This work explores one high-efficiency photocatalytic degradation process of antibiotics, which will help further research in this field.

Unveiling the roles of Fe-Co interactions over ternary spinel-type ZnCoxFe2-xO4 catalysts for highly efficient CO2 hydrogenation to produce light olefins

Currently, the CO2 conversion to light olefins is attractive in clean energy research. Despite numerous works on Co-Fe bimetallic catalysts, the lack of well-defined bulk structures with identical crystalline phase and similar textural property hinders the in-depth understanding of the roles of Fe and Co species. Herein, series of uniform K-containing spinel-type ZnCoxFe2-xO4 nanoparticles (x = 0, 0.5, 1.0, 1.5, 2.0) were successfully synthesized via a single source layered double hydroxide precursor route. Compared to ZnFe2O4 and ZnCo2O4, as-fabricated ternary ZnCo0.5Fe1.5O4 spinel nanoparticles as the catalyst exhibited an outstanding performance toward CO2 hydrogenation to produce light olefins, with a 36.1% selectivity toward C2=-C4= products at a 49.6% conversion and an unprecedentedly high iron time yield for CO2 conversion to light olefins (∼29.1 μmolCO2·gFe−1·s−1) at the gaseous hourly space velocity of 24000 mL·gcat−1·h−1. In combination with structural characterizations and reaction results, it was unveiled that during the CO2 hydrogenation over ternary ZnCoxFe2-xO4 catalysts, the formation of electron-rich Fe0 atoms in the CoFe alloy phase significantly promoted in situ the generation of active iron-cobalt carbide, Co2C, and θ-Fe3C phases, thereby improving the reactivity of catalysts for the production of hydrocarbons and simultaneously inhibiting both the CO2 methanation and the secondary hydrogenation of olefins. The present findings provide a clear understanding of the roles of Fe-Co interactions over ternary ZnCoxFe2-xO4 catalysts for the highly efficient hydrogenation of CO2 to produce light olefins.

Efficient electrocatalytic water splitting by bimetallic cobalt iron boride nanoparticles with controlled electronic structure

Developing an efficient bifunctional catalyst for Hydrogen Evolution Reaction (HER) and Oxygen Evolution Reaction (OER) in water splitting technology is very attractive for clean energy. Here, a new Co-Fe-B ternary catalyst with improved crystallinity is successfully synthesized by combining the chemical reduction and subsequent solid-state reaction method. Synchrotron-based X-ray absorption near-edge structure (XANES) and X-ray photoelectron spectroscopy (XPS) indicate the electronic structure redistribution is favor for the improved performance. The overpotential is only 129 mV and 280 mV for hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) in alkaline condition, the corresponding Tafel slope is 67.3 mV dec−1 and 38.9 mV dec−1. Density functional theory calculations distinguish that the ternary crystalline Co-Fe-B catalysts are thermodynamically favorable for HER and OER. The actual active species of the ternary catalyst in OER is the CoOOH and FeOOH as indicated in ex situ Raman spectra. The present work may introduce promising crystallinity borides material for the anode and cathode of water splitting device.

Double Z-scheme system of α-SnWO4/UiO-66(NH2)/g-C3N4 ternary heterojunction with enhanced photocatalytic performance for ibuprofen degradation and H2 evolution

In this work, we successfully prepared regular hexagonal prism porous structure g-C3N4 (CN), and designed α-SnWO4 and UiO-66(NH2) on porous CN for constructing novel ternary α-SnWO4/UiO-66(NH2)/g-C3N4 (α-SW/UNCN) hybrid photocatalyst by solvothermal approach. The α-SW75/UNCN composite showed better photocatalytic performance, and the removal rate of Ibuprofen (IPF) reached 95.5% within 2 h and the H2 evolution efficiency reached 2105μmolg−1h−1 under simulated sunlight, which were 2.5 times and 21 times higher than those of α-SW (42.5% and 105μmolg−1h−1). The TOC removal efficiency of IPF can reach to 29%, showing higher mineralization ability compared with α-SW. In addition, the trapping experiment and ESR experiment proved that •O2- and •OH radicals played most important part in the photodegradation of IPF pollutants. The improved photocatalytic performance of α-SW/UNCN was owing to the construction of n-p-n type double Z-scheme heterojunction which enhanced carries separation. This work will provide a method for preparing novel and efficiency ternary composite catalyst for antibiotic contaminant degradation and H2 production.

Co- or Ni-modified Sn-MnOx low-dimensional multi-oxides for high-efficient NH3-SCR De-NOx: Performance optimization and reaction mechanism

NH3-SCR performances were explored to the relationship between structure morphology and physio-chemical properties over low-dimensional ternary Mn-based catalysts prepared by one-step synthesis method. Due to its strong oxidation performance, Sn-MnOx was prone to side reactions between NO, NH3 and O2, resulting in the generation of more NO2 and N2O, here most of N2O was driven from the non-selective oxidation of NH3, while a small part generated from the side reaction between NH3 and NO2. Co or Ni doping into Sn-MnOx as solid solution components obviously stronged the electronic interaction for actively mobilization and weakened the oxidation performance for signally reducing the selective tendency of side reactions to N2O. The optimal modification resulted in improving the surface area and enhancing the strong interaction between polyvalent cations in Co/Ni-Mn-SnO2 to provide more surface adsorbed oxygen, active sites of Mn3+ and Mn4+, high-content Sn4+ and plentiful Lewis-acidity for more active intermediates, which significantly broadened the activity window of Sn-MnOx, improved the N2 selectivity by inhibiting N2O formation, and also contributed to an acceptable resistances to water and sulfur. At low reaction temperatures, the SCR reactions over three catalysts mainly obeyed the typical Elye-rideal (E-R) routs via the reactions of adsorbed l-NHx (x = 3, 2, 1) and B-NH4+ with the gaseous NO to generate N2 but also N2O by-products. Except for the above basic E-R reactions, as increasing the reaction temperature, the main adsorbed NOx-species were bidentate nitrates that were also active in the Langmuir-Hinshelwood reactions with adsorbed l-NHx species over Co/Ni modified Mn-SnO2 catalyst.

Ternary Zn1-xNixSe nanostructures as efficient photocatalysts for detoxification of hazardous Congo red, methyl orange, and chrome yellow dyes in wastewater sources

Water contamination by hazardous organic pollutants poses an extreme threat to the environment and globally endangers aquatic life and human health. Hence, the removal of toxic organic effluents from water sources is necessary to ensure a healthy green environment. To this end, a new class of emerging, visible-light-driven Zn- and Ni-based ternary metal-selenide (Zn1-xNixSe) nanophotocatalysts, with tunable nanostructures via regulation of the stoichiometric ratios of Zn and Ni, were synthesized for efficient water purification by a facile one-pot hydrothermal process. These catalysts exhibit outstanding porous properties, with large surface areas and average particle sizes of around 80 ± 10 nm. The as-prepared ternary Zn1-xNixSe catalysts enable improved optical properties, intrinsic conductivity, bandgap reductions, and large numbers of active sites compared with pristine materials, thereby exhibiting outstanding degradation properties against various dye molecules, including Congo red, methyl orange, and chrome-IV upon visible light irradiation. The improved photodegradation capabilities of the Zn1-xNixSe catalysts may be attributed to the synergistic combinations of Zn and Ni selenides, which in turn minimize the recombination rates of the photogenerated carriers compared to their individual constituents. These findings clearly demonstrate that the proposed ternary Zn1-xNixSe catalysts could be potentially used to remove toxic organic contaminants from industrial wastewater.

Au–SnO2–CdS ternary nanoheterojunction composite for enhanced visible light-induced photodegradation of imidacloprid

Herein, we have developed a novel synthetic strategy for the fabrication of Au–SnO2–CdS ternary nano-heterojunction catalyst and its utility towards LED light derived photocatalytic degradation of imidacloprid has been evaluated. The synthesized ternary nanocomposite was characterized using sophisticated analytical techniques to evaluate the catalyst's morphological, structural and surface chemical properties. The photocatalytic activity of the ternary catalyst towards the degradation of imidacloprid was evaluated under LED irradiation. Approximately 95% of the degradation efficiency was achieved with a pseudo-first-order reaction rate of 15.6 × 10−3 min−1. The degradation efficiency of Au–SnO2–CdS nano-catalyst was found to be ~1.2, 1.4 and 2.1 times to that of the pristine Au, CdS and SnO2 nanomaterials under similar experimental conditions. The effect of variation of parameters like contact time, initial pollutant concentration and pH on degradation efficiency has also been investigated. Moreover, the identification of various degradation products and reactive intermediates were made with high-performance liquid chromatography and electron spin resonance techniques.

In Situ Construction of Porous g‐C3N4 Isotype Heterojunction/BiOBr Nanosheets Ternary Composite Catalyst for Highly Efficient Visible‐Light Photocatalytic Activity

AbstractIn this study, the composite catalysts with the heterojunction between DUPG and BiOBr were used to degrade methyl orange (MO), and a g‐C3N4‐based ternary composite catalyst was developed. In our previous work, we prepared a D‐C3N4/U‐C3N4 isotype heterojunction with ordered mesoporous (DUPG) by co‐mixed calcination and hard template method. On this basis, we prepared DUPG/BiOBr nanoparticle uniformly distributed on DUPG nanosheets by coprecipitation self‐assembly method. The hybrids form a tightly coupled heterojunction that enhances the photoactivity and photostability of the DUPG/BiOBr composites. The results show that this tight coupling is beneficial, which facilitates the charge transfer between DUPG and BiOBr, thus promoting the effective separation of photogenerated electron hole pairs. Under visible light irradiation, the methyl orange conversion of the sample has higher photocatalytic reduction activity than BiOBr and DUPG, and its excellent photocatalytic activity is improved by light‐harvesting ability, increased specific surface area, active species and target pollution.

Multicomponent nonprecious hydrogen evolution catalysts for high performance and durable proton exchange membrane water electrolyzer

The commercialization of proton exchange membrane water electrolysis (PEMWE) as an environmentally friendly energy storage technology requires the development of highly active non-Pt catalysts that are stable in acidic media. Nonprecious CuNiMo ternary catalysts with superior activity and durability for the hydrogen evolution are electrodeposited. A wide range of compositions, from Cu and Ni as single metals to binary and ternary alloys, are tested to identify the composition range in which the intrinsic activity is enhanced. In particular, Cu44.4Ni46Mo9.6 exhibits superior electrochemical characteristics, comparable to those of Pt group metals, with a Tafel slope of 27.7 mV dec−1 and an overpotential of 18 mV at −10 mA cm−2. Moreover, during a long-term durability test (24 h at −10 mA cm−2), the overpotential only decays by a few millivolts owing to the modified electronic structure obtained by alloying. PEMWE with Cu44.4Ni46Mo9.6 cathode exhibits 266% higher activity than the average activity of recently reported non-Pt cathode-based PEMWEs at 1.9 Vcell without degradation of performance during 48 h operation. Thus, Cu44.4Ni46Mo9.6 is a promising catalyst for the cost-efficient PEMWE.

Iron polyphthalocyanine-derived ternary-balanced Fe3O4/Fe3N/Fe-N-C@PC as a high-performance electrocatalyst for the oxygen reduction reaction

The oxygen reduction reaction (ORR) is the cornerstone reaction of the cathode in metal-air batteries; however, slow kinetics requires high-performance catalysts to promote the reaction. Polyphthalocyanine (PPc) has a typical chemical cross-linking structure and uniformly dispersed metal active sites, but its poor activity and conductivity limit its applications as an ORR catalyst. Herein, a manageable and convenient strategy is proposed to synthesize ternary ORR catalysts through the low-temperature pyrolysis of FePPc. The optimal catalyst, Fe3O4/Fe3N/Fe-N-C@PC-2.5, exhibits excellent ORR activity in alkaline solution with a half-wave potential of 0.90 V, which is significantly higher than that of commercial 20% Pt/C (0.84 V). Electrochemical tests and extended X-ray absorption fine structure spectroscopy reveal that the superior ORR activity of Fe3O4/Fe3N/Fe-N-C@PC-2.5 could be ascribed to the balance of its ternary components (i.e., Fe3O4, Fe3N, and Fe-N4 species). A Zn-air battery incorporating Fe3O4/Fe3N/Fe-N-C@PC-2.5 as an air cathodic catalyst delivers a high open-circuit voltage and peak power density. During galvanostatic discharge, the battery demonstrates a specific capacity of 815.7 mA h g−1. The facile strategy of using PPc to develop high performance composite electrocatalysts may be expanded to develop new types of catalysts in the energy field.

High activity and durability of a Pt–Cu–Co ternary alloy electrocatalyst and its large-scale preparation for practical proton exchange membrane fuel cells

The large-scale synthesis of catalysts with promising performance and durability for oxygen reduction reaction (ORR) is essential to the industrialization of proton exchange membrane fuel cells (PEMFCs). Pt-based alloys prepared using the co-doping strategy have shown great promise. Herein, we report a co-doping tactic for producing high-performance Pt–Cu–Co ternary alloy catalysts on a mass scale. Cu and Co are doped into the material in one step and the co-doping of Cu and Co can optimize the electronic structure of Pt, thereby weakening the adsorption of oxygenated species with Pt to enhance ORR activity. The PtCu0·72Co0.01 and PtCu0·72Co0.01–10 g (scaled-up production) exhibit superior mass activity of 0.52 A mgPt−1 and 0.43 A mgPt−1, respectively, and peak power density in H2-Air conditions of 1.15 W cm−2 and 1.01 W cm−2. Furthermore, the mass activity of catalysts was only attenuated by 8.3% and 9.5% after 30,000 cycles, indicating reasonably good durability.

Facile synthesis of sphere-like structured ZnIn2S4-rGO-CuInS2 ternary heterojunction catalyst for efficient visible-active photocatalytic hydrogen evolution

Photocatalysis is a promising approach for generating hydrogen, an eco-friendly and cost-effective fuel. It is hypothesized that the ternary catalyst ZnIn2S4-rGO-CuInS2, prepared by ultrasonication method, should be effective for optimized photocatalytic hydrogen generation in a Na2S/Na2SO3−water mixture. The as-synthesized catalyst was characterized using various surface analytical and optical techniques. Field-emission scanning electron microscopy and high-resolution transmission electron microscopy analyses revealed that marigold-like structured ZnIn2S4 and layer-structured CuInS2 were dispersed on the reduced graphene oxide sheets. The ternary ZnIn2S4-rGO-CuInS2 system showed enhanced photocatalytic H2 production compared to pure ZnIn2S4, CuInS2, ZnIn2S4-rGO, CuInS2-rGO, and ZnIn2S4-CuInS2 catalysts under visible light illumination. The fabricated ZnIn2S4-rGO-CuInS2 catalyst afforded hydrogen generation of 2531 μmol/g after 5 h. The enhanced performance of the ZnIn2S4-rGO-CuInS2 catalyst originates from the synergetic effect with rGO as the electron transfer medium, and is confirmed by photocurrent density and photoluminescence measurements that indicate reduced recombination between the excited electron and hole pairs, and fast electron transfer in the ternary composite. The excellent performance of the ZnIn2S4-rGO-CuInS2 catalyst for up to three consecutive cycles was demonstrated in cyclic stability tests under visible-light illumination.

Single-Step Direct Laser Writing of Multimetal Oxygen Evolution Catalysts from Liquid Precursors.

We investigate a laser direct-write method to synthesize and deposit metastable, mixed transition metal oxides and evaluate their performance as oxygen evolution reaction catalysts. This laser processing method enabled the rapid synthesis of diverse heterogeneous alloy and oxide catalysts directly from cost-effective solution precursors, including catalysts with a high density of nanocrystalline metal alloy inclusions within an amorphous oxide matrix. The nanoscale heterogeneous structures of the synthesized catalysts were consistent with reactive force-field Monte Carlo calculations. By evaluating the impact of varying transition metal oxide composition ratios, we created a stable Fe0.63Co0.19Ni0.18Ox/C catalyst with a Tafel slope of 38.23 mV dec-1 and overpotential of 247 mV, a performance similar to that of IrO2. Synthesized Fe0.63Co0.19Ni0.18Ox/C and Fe0.14Co0.46Ni0.40Ox/C catalysts were experimentally compared in terms of catalytic performance and structural characteristics to determine that higher iron content and a less crystalline structure in the secondary matrix decrease the charge transfer resistance and thus is beneficial for electrocatalytic activity. This conclusion is supported by density-functional theory calculations showing distorted active sites in ternary metal catalysts are key for lowering overpotentials for the oxygen evolution reaction.

Localized Surface Plasmon Resonance Enhanced Oxygen Evolution on Nickel-Based Catalysts

Electrochemical localized surface plasmon resonance (LSPR) is an emerging method with applications in sensing and catalysis. In terms of the latter, enhanced oxygen evolution has been demonstrated using nanostructured nickel hydroxide decorated with gold nanoparticles. However, the current state of alkaline oxygen evolution Ni-based transition metal catalysts have obviously expanded beyond monometallic Ni to include additional metals and are prepared using techniques to yield nanostructured catalysts. A variety of these nanostructures are known, with shapes and sizes that vary by synthetic method, and have been extensively studied as water splitting electrocatalysts; however, relatively few have been studied as photoelectrocatalysts which make use of the hot carriers generated by LSPR. We aim to maximize the potential of Ni-based oxygen evolution catalysts as photoelectrocatalysts by applying gold nanoparticle decoration to additional types of nanostructures. Furthermore, by comparing the plasmonic enhancement observed on additional binary and ternary Ni-based catalysts, we hope to elucidate the mechanism of oxygen evolution when the LSPR phenomenon is involved. Additional work may involve the decoration of NiFeLDH nanoplates or spherical structures, as opposed to ordinary nanosheets.