Doping Elements Research Articles

Comparative study of physical properties of As2Se3 and (As2Se3)90Ge10 glassy alloys doped with metallic impurities

To examine the compositional and chemical effects on the glassy system, one must first understand its network structure. Alloying glassy systems cause significant conformal and configurational changes. The optical and physical parameters of As2Se3 and (As2Se3)90Ge10 glassy alloys doped with metallic impurities (X = Bi, Cd, Pb, Sb) have been evaluated. A comparison of the physical properties of glassy alloys has been made as the doping elements increase, i.e., from binary to ternary to quaternary system, and an effort has been made to correlate the optical and physical parameters. The optical density (Dop) and penetration depth (δ) have been calculated from the reported absorption coefficient (α) data. The mean coordination number (<r>) and the number of floppy modes (Mf) calculations show that the floppy regions are decreasing, and hence, the rigidity is increasing when As–Se is doped with Ge and As–Se-Ge is doped with X. The density (ρ) and packing density (PD) have also been evaluated, which are interrelated to the parameters like refractive index (n) and δ. Cohesive energy (CE), mean bond energy (<E>), and glass transition temperature (Tg) values give an insight into the stability and average crosslinking of the system with alloying. The conduction and valence band potentials have supported the optical bandgap (Egopt) values variation.

Influence of Ho, Gd, La Doping on Grain-Grain Boundary Characteristics and Minimization of Leakage Current in Nickel Ferrites

This study explores the impact of doping with Ho, Gd, and La on sol-gel-derived nickel ferrites through a comprehensive analysis using various analytical techniques. The combination of X-ray diffraction (XRD) analysis, X-ray fluorescence (XRF) spectra analysis, impedance spectroscopy, and I-V analysis enables a detailed exploration of the structural, compositional, and electrical characteristics of the samples. Williamson-Hall plots in XRD analysis reveal crucial insights into grain and grain boundary impacts, revealing a shift in trends for doped samples indicative of tensile strain and underscores the influence of dopant ions on lattice distortion. XRF study confirms the elemental composition of the samples, validating the experimental approach. Impedance spectroscopy sheds light on conduction mechanisms and charge transfer processes, while the modulus study identifies distinct relaxation peaks corresponding to grain and grain boundary relaxation mechanisms. IV analysis demonstrates a significant reduction in leakage current with rare Earth element doping, suggesting promising applications.

Curcumin-Assisted Synthesis of MoS2 Nanoparticles as an Electron Transport Material in Perovskite Solar Cells.

Recently, two-dimensional (2D) transition metal dichalcogenides (2D TMDs), such as molybdenum sulfide (MoS2) and molybdenum selenide (MoSe2), have been presented as effective materials for extracting the generated holes from perovskite layers. Thus, the work function of MoS2 can be tuned in a wide range from 3.5 to 4.8 eV by adjusting the number of layers, chemical composition, elemental doping, surface functionalization, and surface states, depending on the synthetic approach. In this proposed work, we attempt to synthesize MoS2 nanoparticles (NPs) from bulk MoS2 using two steps: (1) initial exfoliation of bulk MoS2 into few-layer MoS2 by using curcumin-cholesteryl-derived organogels (BCC-ED) and curcumin solution in ethylene diamine (C-ED) under sonication; (2) ultrasonication of the subsequently obtained few-layer MoS2 at 60-80 °C, followed by washing of the above chemicals. The initial treatment with the BCC-ED/C-ED undergoes exfoliation of bulk MoS2 resulted in few-layer MoS2, as evidenced by the morphological analysis using SEM. Further thinning or reduction of the size of the few-layer MoS2 by prolonged ultrasonication at 60-80 °C, followed by repeated washing with DMF, resulted in uniform nanoparticles (MoS2 NPs) with a size of ~10 nm, as evidenced by morphological analysis. Since BCC-ED and C-ED produced similar results, C-ED was utilized for further production of NPs over BCC-ED owing to the ease of removal of curcumin from the MoS2 NPs. Utilization of the above synthesized MoS2 NPs as an ETL layer in the cell structure FTO/ETL/perovskite absorber/spiro-OMeTAD/Ag enhanced the efficiency significantly. The results showed that MoS2 NPs as an ETL exhibited a power conversion efficiency (PEC) of 11.46%, a short-circuit current density of 18.65 mA/cm2, an open-circuit voltage of 1.05 V, and a fill factor of 58.66%, at the relative humidity of 70 ± 10% (open-air conditions) than that of the ED-treated MoS2 devices without curcumin. These results suggest that the synergistic effect of both curcumin and ED plays a critical role in obtaining high-quality MoS2 NPs, beneficial for efficient charge transport, lowering the crystal defect density/trap sites and reducing the charge recombination rate, thus, significantly enhancing the efficiency.

Thermoelectric properties and effective medium theory analysis on the (GeTe)1-x(InTe)x composites

We employed the p-type semiconductor InTe as an extrinsic phase mixing in the GeTe matrix for thermoelectric properties investigations on the (GeTe)1-x(InTe)x (x=0, 0.02, 0.04, 0.06, and 0.08) composites. We observed notable phenomena that a small amount of InTe has a significant influence on the thermoelectric properties as the primary host matrix in the (GeTe)1-x(InTe)x (x=0.02, 0.04, 0.06, and 0.08) composites. Even for small concentrations of InTe which possess lower thermal and electrical conductivities compared to those of GeTe, the thermoelectric properties of the (GeTe)1-x(InTe)x (x=0.02, 0.04, 0.06, and 0.08) composites are primarily influenced by the properties of InTe. We systematically elucidated the electrical conductivity of the (GeTe)1-x(InTe)x (x=0.02, 0.04, 0.06, and 0.08) composites through the application of effective medium theory (EMT). It is found that the effective media of the (GeTe)1-x(InTe)x (x=0.02, 0.04, 0.06, and 0.08) composites is an asymmetric medium insulator. The addition of InTe into GeTe reveals a significant decrease in total thermal conductivity due to reductions in both electronic and lattice thermal conductivity. Particularly, the decrease in lattice thermal conductivity was attributed to an increase in internal strain within the lattice induced by the addition of InTe. Consequently, the ZT values of the composite significantly increase across all temperature ranges. This study suggests that developing composites is an effective approach for enhancing thermoelectric performance, comparable to elemental doping, and demonstrates the ability to analyze the electrical properties of composite materials using EMT.

Rare earth doped bimetal hydroxide/multi-walled carbon nanotubes as composite electrodes to achieve high-energy-density asymmetric supercapacitors

A novel electrode material of Ni–Co bimetallic hydroxide composite multi-wall carbon nanotubes (La–NiCo LDH/MWCNTs/NF) doped with rare earth elements was prepared on nickel foam (NF) by a one-step hydrothermal method and doped with different concentrations of La3+ ions. The introduction of La3+ ions can increase the layer spacing of LDH materials. The acidification of MWCNTs on the surface of NF can also enhance the collection effect of NF. The synergistic effect of MWCNTs and La3+ ions further improves the specific capacitance of the material. At the current density of 1 A g−1, the maximum specific capacitance of the sample with 5 % La3+ ion concentration reaches 4396.0 F g−1, and the capacitance retention is 70.31 % after 3000 cycles of a single electrode. When assembled into a device, the device obtains a high energy density of 77.86 Wh kg−1 at a power density of 800.0 W kg−1. After assembling into an asymmetric supercapacitor, it has undergone 8000 cycles of performance testing, and the capacitance ratio is only reduced by 4.9 %. It shows good electrochemical cycle performance. This work provides a new way to study the doping of rare earth elements for supercapacitor materials.

Doping and strain effect on the catalytic performance of Tin+1CnO2 (n = 2, 3) for hydrogen evolution reaction

Mxenes has attracted wide attention due to its advantages of high conductivity, diverse composition, thinness and adjustable structure. In this paper, we systematically calculated adsorption energy, Gibbs free energy, and exchange current density of Ti3C2O2 and Ti4C3O2. The effect of H-coverage, element (Cr, Hf, Mo, Nb, Ta, V) doping and strain application on the HER catalytic performance were also analyzed. The results show that Ti4C3O2 has stronger catalytic ability than Ti3C2O2. H coverage is negatively correlated with catalytic performance of Tin+1CnO2 (n = 2, 3). Among calculated doping elements, for improving catalytic ability of Ti3C2O2, V or Mo doping is beneficial. While for Ti4C3O2, only Mo doping is beneficial. Furthermore, compression strain of −5%, −3%, −1% is beneficial for improving catalytic performance of Ti3C2O2 and Ti4C3O2. Our work reveals the microscopic mechanism of MXene catalyzing HER, which is useful for the further development of water electrolysis catalysts.

Grain boundary engineering in Nickel-rich cathode: A combination of high-throughput first-principles and interpretable machine learning study

One of the primary challenges in commercializing nickel (Ni)-rich layered cathodes for lithium-ion batteries (LIBs) is addressing the problem of crack formation during cell cycling. These cracks quickly spread along grain boundaries (GBs), causing capacity and voltage degradation. GB engineering, a classical technique for strengthening materials that has been largely unexplored in LIBs, could potentially inhibit intergranular fractures and significantly extend battery life. In this study, we employed a synergistic approach that combined high-throughput first-principles calculations and an interpretable machine learning (ML) framework to assess the feasibility of enhancing GBs through segregation-induced strengthening via doping. As a result, we generated a comprehensive database containing 64 elements doped at 4 sites in ∑3 [100](012) GB of LiNiO2, representing the largest database for first-principle-aided GB engineering in LIBs to date. This database further enabled the implementation of an interpretable ML workflow to uncover the fundamental principles governing dopant segregation and GB strengthening. Based on the insights gained from this research, we provide practical and promising recommendations for dopant elements that can effectively anchor and reinforce GBs, such as Mg, Al, Si, Ti, Cr, Mn, Fe, Cu, Zn, Hf, and Ce, with some already demonstrated success in experiments. This work on GB engineering serves as a foundation for the development of advanced, doped cathode materials for next-generation batteries.

Tailoring Auger Recombination Dynamics in CsPbI3 Perovskite Nanocrystals via Transition Metal Doping.

Auger recombination is a pivotal process for semiconductor nanocrystals (NCs), significantly affecting charge carrier generation and collection in optoelectronic devices. This process depends mainly on the NCs' electronic structures. In our study, we investigated Auger recombination dynamics in manganese (Mn2+)-doped CsPbI3 NCs using transient absorption (TA) spectroscopy combined with theoretical and experimental structural characterization. Our results show that Mn2+ doping accelerates Auger recombination, reducing the biexciton lifetime from 146 to 74 ps with increasing Mn doping concentration up to 10%. This accelerated Auger recombination in Mn-doped NCs is attributed to increased band edge wave function overlap of excitons and a larger density of final states of Auger recombination due to Mn orbital involvement. Moreover, Mn doping reduces the dielectric screening of the excitons, which also contributes to the accelerated Auger recombination. Our study demonstrates the potential of element doping to regulate Auger recombination rates by modifying the materials' electronic structure.

Nonmetallic element-doped graphene aerogel enhances industrial wastewater removal performance via a multifield coupled system of adsorption-catalytic degradation: Insights from experiments and theoretical calculations

In this paper, a multifield coupled system of synergistic adsorption and photo-Fenton degradation was constructed, and BiFeO3-modified nonmetallic element-doped graphene aerogel composites (BiFeO3/X-rGA) were prepared to realize the advanced treatment of phenol and coking wastewater by utilizing consistent adsorption and catalytic degradation sites. Nonmetallic element-doped graphene formed more defective active sites and changed the planar carbon layer structure, which enhanced the adsorption performance of pollutants on the basis of graphene face adsorption and π-π adsorption. Moreover, element doping also modulated the localized electronic structure of graphene and promoted carrier separation, which in turn enhanced the photo-Fenton degradation activity. The phenol degradation rate constant of BiFeO3/P-rGA was 3.29 times greater than that of BiFeO3/rGA, and the removal efficiency in coking wastewater was also greatly improved. In coupled systems, hydroxyl radicals are the predominant active species, and the mechanism by which nonmetallic modifications promote the synergistic performance of graphene aerogel adsorption and catalytic degradation systems was refined based on experimental and DFT results, providing a new idea for the advanced treatment of wastewater.

The synergistic effect of Ta-doping and antireflective TaOx layer on the thermochromic VO2 thin films for smart windows

Current efforts to promote the use of VO2 materials as a promising candidate for thermochromic smart windows continue to be hindered by the low luminous transmittance (Tlum), the limited solar modulation ability (ΔTsol), the high phase transition temperature (Tt, ∼68 °C) and the wide thermal hysteresis (ΔT). The present work addresses these issues by fabricating an antireflective TaOx layer on the Ta-doped VO2 (i.e., VO2(Ta)) thin films. The VO2(4.35 at% Ta) thin films with low Tt of 29.87 °C and narrowed ΔT of almost zero were grown on glass substrates by magnetron sputtering at room temperature followed by rapid thermal annealing. However, the VO2(Ta) thin films show slightly enhanced Tlum of 38.31 % compared with undoped VO2 films (35.46 %) and decreased the ΔTsol by 1.83 %. The thermochromic properties are further enhanced by depositing the antireflective TaOx layer onto the VO2(Ta) thin film by reactive magnetron sputtering, which significantly increases the Tlum from 38.31 % to 48.58 %, marginally decreases the ΔTsol from 4.44 % to 4.12 %, and maintain the Tt and ΔT constant. These results verify the possibility of developing VO2 films with simultaneously increased optical transmittance, decreased Tt to suitable values, and extremely narrow ΔT by using the synergistic effect of element doping and constructing an antireflective layer.

Boosting Solar Water Splitting Performance of Cu3BiS3‐Based Photocathode via Ag Doping Strategy

AbstractA photovoltaic wittichenite semiconductor of Cu3BiS3, due to its optimal bandgap, high light absorption coefficient, and various advantages of low cost and environmental‐friendliness, has been considered a competitive candidate for solar absorber materials of photocathode for photoelectrochemical water splitting. However, the presence of various deleterious defects in the Cu3BiS3 lattice and its high conduction band minimum are detrimental factors that restrict further enhancements in the conversion efficiency of Cu3BiS3‐based photocathode. Herein, a one‐step solution‐based Ag element doping strategy is proposed to improve the crystalline quality of Cu3BiS3 films, which includes enlarging the grain size and reducing the intergranular gaps. Additionally, the Ag‐doped Cu3BiS3 layer can form a more favorable band alignment with the buffer layer. Ultimately, the fabricated composite Cu3BiS3‐based photocathode doped with 3% Ag delivers a remarkable photocurrent density of 13.6 mA cm−2 under 0 VRHE, an applied bias photon‐to‐current efficiency of 2.85%, and long‐term stability exceeding 12 h. Furthermore, with the assistance of a BiVO4 photoanode, the tandem cell also achieves an unbiased solar‐to‐hydrogen efficiency of 2.64%, with no significant decline observed within 20 h.

Comprehensive improvement of AB2 hydrogen storage alloy: Substitution of rare earth elements for different A-side alloys

Rare earth substitution enhances the activation, absorption/desorption properties of hydrogen storage alloys, a crucial research area. Despite the extensive variety of A-site elements in multicomponent alloys, there remains a scarcity of reports on how to enhance the hydrogen storage capacity of alloys by substituting different elements with rare earth elements at the A-site, which needs to be further explored. In this study, the AB2 type Ti-Mn based hydrogen storage alloy was selected as the research object, and the effect of replacing different elements in the A-position by rare earth elements with equal atomic ratios was systematically analyzed by replacing the hydrogen absorption elements Ti/Zr with the rare earth metal Ce. The result reveals that Ce substitution significantly enhances the hydrogen storage and cyclic performance of the alloys, with Ce substituting for Ti showing superior performance. Theoretical calculations indicate that Ce substitution for Ti in alloys leads to lower formation energy and easier hydrogen absorption than Ce substitution for Zr. Beyond the influence of the Lundin’s theory, this work proposes for the first time that the difference in electronegativity between substituent elements may one of the crucial factors affecting the hydrogen storage performance of alloys. The greater difference in electronegativity may lead to a higher hydrogen storage capacity of the hydrogen storage alloy. This opens a new avenue for research into doping/substitution modifications of hydrogen storage alloy elements. These findings not only enrich the knowledge on element doping modification but offer valuable insights for future research on rare earth-doped modification of hydrogen storage alloys.

Perovskite nanowire-based electrochemical sensing for selective and rapid detection of hydrogen peroxide

Nanowires possess inherent advantages in improving the reduction of boundary stacking defects and enhancing charge transfer or migration. Here, we synthesized all-inorganic perovskite nanowires CsPbBr3 (PVSK NW) and obtained CsPb1-xSnxBr3 (PVSK-Sn NW) and CsPb1-xGexBr3 (PVSK-Ge NW) nanowires through doping with different elements (Sn and Ge). Elemental doping endows the nanowires with unique narrow fluorescence spectra, high optical absorption coefficients, tunable optical bandgaps, and high carrier mobility. Introducing different perovskite nanowires into carbon-based composite materials (super p/Nafion) can overcome the challenges of hydrogen peroxide (H2O2) detection sensitivity and matrix interference. H2O2 in PBS (phosphate buffered saline) solution (pH 7.0) was detected by current analysis i-t curve mode. The results demonstrate that the addition of perovskite nanowires exhibits a high level of detection sensitivity for H2O2 electrochemical reduction. Particularly, the linear concentration range detected by PVSK-Sn NW is 1–6000 µM, with a detection limit of 0.12 µM. Even in the presence of interfering molecules (ascorbic acid, uric acid, glucose), the detection of H2O2 maintains high sensitivity and selectivity. This study overcomes the limitations of perovskite materials in water-based detection, enhancing their future commercial applications as sensing devices.

Nonmetal Substitution in Interstitial Site of O3‐NaNi0.5Mn0.5O2 Induces the Generation of a Nearly Zero Strain P2&amp;O3 Biphasic Structure as Ultrastable Sodium‐Ion Cathode

AbstractCo‐free O3‐type NaNi0.5Mn0.5O2 cathode material for sodium‐ion batteries has shown great promise due to its high theoretical capacity and plentiful Na reservoir. However, the rapid capacity recession caused by harmful phase transition and large volume strain severely restricts their practical application. Herein, the obstacle is well addressed by constructing a P2&amp;O3 biphasic structure via a customized boron‐doping strategy. The light‐weight boron doping in the interstitial position reduces the energy gap of the formation energy of P2 and O3 structure, which induces the formation of P2&amp;O3 biphase in high Na state. In addition, the biphasic structure exhibits near zero volume strain due to the lattice interlocking effect of P2&amp;O3, as identified by in situ X‐ray diffraction measurement. As a result, it presents a remarkable cyclability with a capacity retention of 85.2% over 1000 cycles at a high rate of 5 C. More importantly, a pouch‐type full‐cell device can exhibit a long cycling life with 70.8% capacity retention over 150 cycles at 0.1 C. This work can offer a new inspiration for designing advanced high sodium electrode materials via light element doping for future energy storage devices.

Enhanced visible light photocatalytic activity of SDBS/C/Nd/TiO2 synthesized by using anionic surfactant SDBS as template agent

&lt;p&gt;The catalyst SDBS/C/Nd/TiO2 was synthesized by sol-gel method using TiO2 co-doped with C and Nd and anionic surfactant SDBS as template agent. The prepared photocatalysts were characterized by X-ray diffraction (XRD), scanning electron (SEM), X-ray photoelectron spectrometer (XPS) and UV-vis diffuse reflectance spectroscopy (UV-vis DRS) and so on. Experimental results show that the crystal structure of the catalytic material is anatase type. Since doped elements change the energy band structure and electronic structure of TiO2, photogenerated electrons and holes can transition through the intermediate energy level, resulting in a decrease in the required excitation energy, thereby increasing the distance of its absorption edge moving toward the long wave direction, and meanwhile improving the utilization rate of visible light. The bandgap energy of the catalyst SDBS/C/Nd/TiO2 was 2.78 eV. Compared to pure TiO2 (3.1 eV), the band gap is reduced by 0.32eV. The photocatalytic experiments show that the degradation rate of the catalyst SDBS/C/Nd/TiO2 for methyl orange solution can reach 67%, and the catalytic performance is much improved than that of pure TiO2.&lt;/p&gt;

Preparation of LiLaZrMO (M= Ga/Al) solid electrolytes for thermal batteries

Thermal batteries (TBs) are ideal power sources for high temperature environment due to their high specific energy, long storage time, and quick activation. However, the common molten salt electrolytes (MSE) suffer from overflow under overload or high spin state, which could lead to short circuit of the batteries. To address this issue, LiLaZrMO (LLZMO, M = Ga/Al) doped with different elements are prepared. The doping elements result in the phase change of LiLaZrO (LLZO) from tetragonal to cubic, alters the distribution of Li atoms and increases the ion transport bottleneck sizes. In particular, LiLaZrGaO (LLZGO) has the lowest activation energy (0.3 eV) and the highest total conductivity (2.57 × 10−2 S cm−1 at 500 °C) owing to the larger bottleneck and unique Li+ transport channel. TB with LLZGO provides the highest discharge specific capacity of 368.5 mAh g−1 and lowest internal resistance (0.23 Ω cm−2). Compared with the ones using LiF–LiCl–LiBr MSE, TB with LLZGO solid electrolyte (SE) also shows superior performance in pulse discharge capabilities due to the stable internal resistance as well as the fluctuation free characteristics. Therefore, LLZGO SE holds great potential as viable alternative to MSEs in TBs.

Effect of Bi-Er-O addition on the electrical properties of ZnBiCoMnSb based varistor

In order to restrain the breakdown voltage gradient E1 mA at a low level and simultaneously improve nonlinear coefficient α, the rare earth element Er was doped into ZnBiCoMnSb based varistor ceramic in the form of Bi-Er-O phase. As a result, the excellent electrical performances including low E1 mA of 190 V/mm, high α of 55.6 as well as low leakage current IL of 2.5 μA/cm2 are obtained in 3 wt% Bi-Er-O phase modified ZnBiCoMnSb based varistor ceramic. It is found that the concentration of Er at grain boundaries is slightly higher than that in ZnO grains, while it is uniformly distributed throughout the bulk ceramic. This characteristic of element distribution mainly contributes to the enhancement of α by forming interface state densities and deep bulk traps at grain boundaries, rather than E1 mA. The reported herein strategy to restrain E1 mA and improve α at the same time on ZnBiCoMnSb based varistor ceramic can act as a reference for further fabrication of low-E1 mA varistor ceramics with excellent nonlinear performances by rare earth elements doping.

Investigation of thermal stability improvement in Nb doped Sb2Te3

The phase change material Sb2Te3 (ST) exhibits a fast-switching speed and poor thermal stability because the four-fold rings are dominant and homo-polar bonds are absent in the amorphous state. Many studies have been performed on the improvement of phase change properties. Chemical doping methods have been widely used because additional chemical bonds are formed between the doped element and host atoms, leading to the modification of the local structure and electronic band structure. Previous reports have indicated the importance of the bond length and lattice mismatch in element doped ST. In this study, the electronegativity of the doped elements was investigated because it determines the strength of the bond via charge transfer between two atoms. A strong correlation between the electronegativity of the doped element and the phase change properties of the doped ST was observed. An ideal electronegativity range, which corresponds to some elements doped ST with excellent thermal stability, was found in this investigation. Nb atoms were selected as the optimal dopant to stabilize the amorphous phase of ST because Nb was in the ideal range. Additional homo-polar bonds and Nb-Te bonds can stabilize the amorphous phase because additional energy is required for ring reconstruction during crystallization. Consequently, the thermal stability and resistance difference of the Nb doped ST were significantly improved. In addition, the phase change speed of ST was not affected by Nb doping. This study highlights a new approach for pursuing better properties of phase change materials by chemical doping methods.

First-principles study on the Te/Po doped SrTiO3 (100) surface for photocatalytic overall water splitting to produce hydrogen

The (100) surface of SrTiO3 is inefficient for solar photocatalytic performance because its wide bandgap restricts the response to visible light. The effects of the different surface termination and the doped atoms are investigated to manipulate the solar photocatalytic behavior of the surface. The results reveal that the band edges for the Ti/O-terminated (100) surface of SrTiO3 (SS-I) can straddle the redox potentials for the hydrogen evolution reaction (HER) and oxygen evolution reaction (OER), but this is not true for the Sr/O-terminated one (SS-II). However, we successfully make the band edges of SS-II meet the HER and OER conditions by the doped Te and Po atoms (Te-SS-II and Po-SS-II), after trying the doped elements of the IIIA-VIA group. The solar-to-hydrogen efficiency are 14.50 %, 9.89 %, and 12.75 % for SS-I, Te-SS-II, and Po-SS-II, respectively. The Gibbs free energies are calculated for each HER and OER. The result of -0.34 eV for the HER on SS-I indicates that this reaction can spontaneously proceed. Therefore, these surfaces are promisingly used for photocatalytic water splitting. The present findings provide helpful guidance to manipulate the photocatalytic water splitting on the (100) surfaces of SrTiO3 by choosing the terminal atoms or doped atoms on the surface.

Montmorillonite‐supported Ru‐doped CuBi2O4 nanozyme with enhanced peroxidase‐like activity for sensitive determination of hydroquinone

Nanozymes constitute a category of nanomaterials presenting the potential to replace natural enzymes. Nonetheless, weak catalytic activity becomes the biggest barrier hindering their practical applications. In this study, we fabricated a montmorillonite (MMT)‐supported ruthenium (Ru)‐doped CuBi2O4 nanozyme (Ru/CuBi2O4‐MMT) with robust peroxidase (POD)‐like activity by hydrothermal method and studied its application in determination of hydroquinone (HQ). Specifically, the CuBi2O4 material is brought into nanozyme field for the first time. MMT‐supported CuBi2O4 material possesses smaller size and larger surface area than pure CuBi2O4. Ru‐doped exhibits significantly higher POD‐like activity in comparison to CuBi2O4 due to the increase of defect sites. Both of strategies synergistically enhance the POD‐like activity of CuBi2O4 material. The POD‐like activity of nanozyme originates from the photogenerated holes (h+) and superoxide radicals (•O2−) produced during the catalytic decomposition of H2O2. Ru/CuBi2O4‐MMT nanozyme can be successfully applied for HQ colorimetric detection by redox reaction. Our newly developed nanozyme exhibits exceptional POD‐like activity by introducing support and element doping strategies, holding great potential for detecting pollutants in practical applications.