Ce Co-doping Research Articles

Synergistic impact of lanthanum and cerium co-doping ZnO for improved photocatalytic rhodamine B degradation efficiency under UV light

In this study, the influence of different La and Ce co-doping amounts on the structural, morphological, optical, and photodegradation properties of ZnO nanostructures was evaluated. Zn1-2xLaxCexO nanoparticles (NPs) were prepared using sol-gel auto-ignition process, where x = 0.00 (pure ZnO), 0.01 (LC1), 0.03 (LC3), and 0.05 (LC5). The X-ray diffraction (XRD) and Raman results revealed that the prepared ZnO NPs crystallize in the hexagonal wurtzite structure. The size of crystallites is affected by the increment of La and Ce and it decreased from 24.29 nm to 10.40 nm with the increase in the concentration of La and Ce. Transmission electron microscopy (TEM) showed that the samples exhibit an irregular distribution of NPs with a dominant spherical shape morphology. The simultaneous incorporation of La and Ce in ZnO NPs led to a slight variation in the absorption edge and a slight shift in the values of the band gap energy from 3.20 to 3.24 eV. Furthermore, a reduction in the recombination rate of photogenerated charge carriers and the creation of fewer additional defects upon the appropriate insertion of Ce and La ions are highlighted by the analysis of photoluminescence spectra, Nyquist plots, and transient photocurrent measurements. The photocatalytic activity of samples was evaluated against rhodamine B organic dye under UV light irradiation. The analysis showed that LC1 sample exhibited superior photocatalytic performance with 99.1% degradation efficiency and a degradation rate constant of 0.0762 min-1. This enhancement has been ascribed to the surface defects and the optimized crystallite size achieved, which help to generate reactive entities such as •OH and O2•− in addition to the great role of holes (h+) and impede the recombination of charge carriers e-/h+.

Electronic regulation of Ce,F-Ni2P/CoP catalyst for efficient water splitting

Designing efficient non-precious-metal bifunctional electrocatalysts is still challenging at present. Herein, the efficient Ce,F-Ni2P/CoP electrocatalyst for water splitting was successfully fabricated. As shown from the present investigation, the codoping of Ce and F in Ni2P/CoP induced the f-p-d gradient orbital coupling in the Ce-F-metal structural unit of the catalyst, significantly reducing the work function of the catalyst, which accelerated the reaction kinetics and improved the intrinsic catalytic activity. The catalyst exhibited the outstanding hydrogen evolution reaction (HER) activity in the full pH range and, especially in alkaline electrolyte, an ultra-low oxygen evolution reaction (OER) overpotential of 243 mV at 50 mA·cm−2 and an excellent HER overpotential of 88 mV at 10 mA·cm−2 were achieved. Moreover, Ce,F-Ni2P/CoP displayed an excellent overall water splitting (OWS) performance with η10 = 1.52 V. DFT theoretical calculations also showed that the gradient orbital coupling resulted in the reduction of the work function of the catalyst. Our work provides a new understanding of designing and constructing high-performance catalysts.

(Ce, Nd) co-doped TiO2 NPs via hydrothermal route:Structural, optical, photocatalytic and thermal behavior

Rare earth (Ce, Nd) doped/co-doped titania (TiO2) nanoparticles were successfully produced by hydrothermal route. Titanium isopropoxide (IV), cerium nitrate hexahydrate and neodymium nitrate hexahydrate were utilized as raw/starting materials. The effect of Ce and Nd doping/co-doping in TiO2 were studied through different complementary tools such as XRD, FTIR, FE-SEM, EDX, XPS, UV–Visible, PL, photocatalytic and thermal analysis. XRD spectra revealed anatase tetragonal phase and cubic phase due to titania and ceria nanoparticles respectively. The crystallite size, lattice constants, volume and no. of unit cell were determined through XRD data. Optical studies revealed the band gap, urbach energy, extinction coefficient, refractive index, optical conductivity and photoluminescence emission wavelength. FTIR spectra investigated the chemical bondings and functional groups present in prepared samples. Optical absorption spectra confirmed that absorption edge is red shifted, indicating a decrease in band gap from 3.5 to 3.0 eV with the incorporation of rare earth ions (Ce, Nd) in TiO2 matrix. The rate of electron-hole pair recombination was reduced through co-doping of (Ce, Nd) in TiO2 lattice as exhibited by reduction in intensity of photo luminescence spectra. The photocatalytic efficiency was enhanced with the integration of rare earth metal ions in TiO2 matrix for different dyes such as rhodamine B (RhB) and malachite green (MG) with visible light irradiation. The degradation efficiency of (Ce, Nd) co-doped TiO2 NPs against RhB and MG dyes was found to be 89 and 95 % respectively. TGA analysis was carried out to find weight loss during different thermodynamic phases such as dehydration, decomposition and combustion, and crystallization. Various thermodynamic parameters such as activation energy, entropy and enthalpy were estimated by thermal analysis.

Fe,Ce Co-Doped Ni3S2/NiS Polymorphism Nanosheets with Improved Electrocatalytic Activity and Stability for Water Oxidation.

Balancing the relationship between electrocatalytic activity and stability of sulfide catalysts during oxygen evolution reaction (OER) has been attracting extensive research interest. Here, a simple electrodeposition-vulcanization two-step route was designed to successfully construct nickel foam supported sheet-like Fe,Ce-codoped Ni3S2/NiS polymorphism catalyst (labeled as Fe,Ce-Ni3S2/NiS/NF). Electrochemical measurements showed that the as-obtained Fe,Ce-Ni3S2/NiS/NF electrode presented excellent OER electrocatalytic performances. In 1 M KOH solution, merely 173 and 234 mV of overpotentials were required to deliver the current densities of 10 and 100 mA cm-2, respectively. Further investigations revealed that the Fe,Ce co-doping regulated the electron density around Ni, which promoted the conversion of Ni towards the higher valence state and simultaneously, avoided the stability decrease of the catalyst caused by excessive oxidation corrosion. Moreover, the defects generated during vulcanization also contributed to promoting water oxidation. The present work provides a facile and feasible approach to balance the relationship between the stability and the activity of sulfide catalysts for OER.

Regulation of photoelectric properties of multi-element (Sn, Fe, Ce) co-doped anatase TiO2: The first principles study

The energy band structure, density of states and optical properties of multi-element (Sn, Fe, Ce) co-doped anatase titanium dioxide have been calculated using the first principles method. The results show that two-element (Sn, Fe, Ce) doping affects the energy band structure more than the single doping behaviour. Co-doping of two of the three elements (Sn, Fe, Ce) reduced the energy band gap values of TiO2 compared to pure anatase TiO2.The forbidden bandwidths of Sn and Ce were smaller than those of mono-doped Sn, but the co-doped system had higher bandwidth narrowing than that of the mono-doped system. The co-doping of Sn and Ce is 0.206 eV smaller than the single doping of Sn, and the co-doping of Sn and Fe is 0.56 eV smaller than the single doping of Sn. The utilization of the regional light absorption is increased, and the absorption spectra are red-shifted. It can be seen that the co-doping method is more favourable to the improvement of visible light response and visible photocatalytic activity of TiO2 than the single doping method.

Combined experimental and first principles look into (Ce, Mo) doped BiVO4

Here we investigated the effects of Ce and Mo doping on hydrothermally synthesized bismuth vanadate BiVO4 nanoparticles (NPs). The existence of monoclinic scheelite and tetragonal zircon phases of NPs was validated from Rietveld refinement of the powdered X-ray diffraction, room temperature Raman, and Fourier-transform infrared spectroscopy. The co-doping of Bi and V sites with respective Ce and Mo dopants in a mixed tetragonal zircon and monoclinic scheelite phases of BiVO4 lattice was corroborated from high-resolution transmission electron microscopy and X-ray photoelectron spectroscopy. The photoluminescence measurements revealed enhancement of photo-generated carrier recombination in (Ce, Mo) co-doped BiVO4 NPs which may have hampered its photocatalytic efficiency in degrading the methylene blue dye. The simulations based on Hubbard U corrected density functional theory (DFT+U) suggest that Mo and Ce co-doping introduced deep impurity states which may have facilitated the photo-generated carrier recombination detrimental to photocatalytic performance. The UV-vis diffuse reflectance measurements provided evidence for the presence of these defect states. In summary, this work may have presented a comprehensive experimental analysis of (Ce, Mo) doped BiVO4 supported by DFT simulations.

Promotion effect of Ce and Ta co-doping on the NH3-SCR performance over V2O5/TiO2 catalyst

NH3-SCR (SCR: Selective catalytic reduction) is an effective technology for the de-NOx process from both mobile and stationary pollution sources, and the most commonly used catalysts are the vanadia-based catalysts. An innovative V2O5-CeO2/TaTiOx catalyst for NOx removal was prepared in this study. The influences of Ce and Ta in the V2O5-CeO2/TaTiOx catalyst on the SCR performance and physicochemical properties were investigated. The V2O5-CeO2/TaTiOx catalyst not only exhibited excellent SCR activity in a wide temperature window, but also presented strong resistance to H2O and SO2 at 275 ℃. A series of characterization methods was used to study the catalysts, including H2-temperature programmed reduction, X-ray photoelectron spectroscopy, NH3-temperature programmed desorption, etc. It was discovered that a synergistic effect existed between Ce and Ta species. The introduction of Ce and Ta enlarged the specific surface area, increased the amount of acid sites and the ratio of Ce3+, (V3++V4+) and Oα, and strengthened the redox capability which were related to synergistic effect between Ce and Ta species, significantly improving the NH3-SCR activity.

Effect of Tb3+ and Ce3+ Co-doping on the Structure and Photoluminescence Properties of Hexagonal Boron Nitride Phosphors.

In the paper, we have successfully prepared hexagonal boron nitride (h-BN:Tb3+, Ce3+) phosphors with melamine as the nitrogen source. The X-ray powder diffraction patterns confirm that the sample possesses a hexagonal crystal structure within the P m2 space group. It is interesting that the co-doping combination of Tb3+ and Ce3+ can markedly enhance the threshold concentration of doped activators within the limited solid solution of h-BN phosphors. Under 302nm excitation, the h-BN:Ce3+ phosphors exhibit broadband blue light emission at 406nm. In h-BN:Tb3+, Ce3+ phosphors, the co-doping of Ce3+ not only ensures high phase purity but also results in strong green light emission. The energy transfer efficiency from Ce3+ to Tb3+ is about 55%. The fluorescence lifetime increases with the increase of Ce3+ and Tb3+ concentration, and the fluorescence lifetime of h-BN:0.025Tb3+, 0.05Ce3+ phosphor reached 2.087ms. Additionally, the h-BN:0.025Tb3+, 0.05Ce3+ phosphor exhibits excellent thermal performance with an activation energy value of 0.2825eV. Moreover, the photoluminescence quantum yield of the sample exceeds 52%. Therefore, the h-BN:Tb3+, Ce3+ samples can be used as green phosphors for solid state lighting and fluorescent labeling.

Effect of P and Ce co-doping on the photocatalytic performance of g-C3N4: Experimental and theoretical studies

Element doping strategies are commonly employed to achieve effective photocatalysts. In this work, a novel form of P and Ce co-doped g-C3N4 nanosheets was synthesized using a one-step thermal polymerization technique, exhibiting remarkable efficiency in the degradation of organic pollutants under visible light. The prepared catalysts underwent comprehensive characterization through XRD, FT-IR, SEM, TEM, BET, XPS, UV–vis, PL, and electrochemical testing. The electronic and optical properties of the catalysts were further elucidated using first-principles density functional theory (DFT). In the photocatalytic experiment of degrading Rhodamine B (RhB), the photocatalytic ability of g-C3N4 nanosheets was improved at different degrees, among which g-C3N4 nanosheets co-doped with P and Ce showed the highest photocatalytic activity, with a degradation efficiency of 90.58 % for RhB. Furthermore, the photocatalytic mechanism was confirmed through free radical capture experiments. This study presents a novel approach for the development of efficient photocatalysts to remove pollutants.

Optimizing synthesis strategies for the production of single-phase zirconates with Ce and Nd co-doping

Zirconia-based ceramics are promising host matrices for the immobilization of radionuclides in high-level waste streams due to their high radiation resistance and chemical stability. This study explores coprecipitation and different solid-state synthesis techniques to produce phase-pure zirconia-based ceramics with varying cerium and neodymium co-doping. Varying the dopant concentration enabled the synthesis of zirconates with monoclinic, cubic defect fluorite, and cubic pyrochlore structures. Powder X-ray diffraction was used for phase identification. In the case of coprecipitation, all synthesized compositions were predominantly phase-pure. Solid-state synthesis techniques included manual mixing of metal oxide powders with mortar and pestle, mechanical mixing in a ball mill, and magnetic mixing in a slurry. All solid-state mixing methods produced heterogeneous ceramics, featuring multiple phases, with manual mixing yielding the most phase-pure product. Extending the grinding time, re-sintering of the solid phases, and an increased Nd content were found to enhance the phase purity.Graphical abstract

Growth of GSAG:Ce scintillation crystals by the Bridgman method: influence of Ce concentration and codoping

Illustrative decays highlight the range of rise (15 to 45 ns) and decay times (27 to 76 ns).

Effect of in-situ formation of CeH2.73/CeO2-x and V2O3 on hydrogen storage performance of MgH2

MgH2, one of the most promising lightweight hydrogen storage mediums, has aroused intensive attention due to its outstanding reversible hydrogen storage capacity. However, it suffers from the intrinsic high operating temperature and sluggish kinetics from de-/hydrogenation, hindering its further industrial application. Herein, we successfully synthesized a novel rare earth Ce co-doping with V element forming bimetallic oxide additive, CeVO4 nanoparticles, which exhibits an excellent catalytic effect for enhancing the hydrogen storage performance in MgH2. With an optimization addition of 10 wt% CeVO4, the initial dehydrogenation temperature of the composite decreased from 286 °C to 212 °C. The composite can desorb 6.03 wt% H2 within 6 min at 300 °C and absorb 1.9 wt% H2 within 20 min even at a low temperature of 50 °C. The apparent dehydrogenated activation energy of the composite was obtained as 61.38 ± 3.9 kJ mol−1. The catalyst mechanism analysis revealed that the “hydrogen pumping” effect of the in-situ formed CeH2·73/CeO2-x and V2O3 play a crucial role in boosting the de-/hydrogenation properties of CeVO4-catalyzed MgH2. This work is helpful for further rational designs of novel catalysts in promoting the commercialization of MgH2.

Biomimetic photocatalyst Ce/TCPP-UiO-66-NH2 for NADH regeneration and CO2 activation

CO2 activation and conversion by enzymes to produce value-added multi-carbon compounds under mild conditions show significant impact on carbon neutrality. However, the enzyme co-factor NADH is expensive and the regeneration is still challenging for the enzyme reaction process. Inspired by natural photosynthesis, this study successfully developed a biomimetic photocatalyst Ce/TCPP-UiO-66-NH2 (TCPP: meso-tetrakis (4-carboxyphenyl) porphine) for NADH regeneration and CO2 activation. Structure analysis and spectra showed that the co-doping of Ce and TCPP reduced the band gap width of UiO-66-NH2, improved the separation efficiency of photo-generated carriers, and endowed it with excellent photocatalytic performance. The synthesized biomimetic photocatalyst Ce/TCPP-UiO-66-NH2 was then applied for NADH regeneration. The regeneration efficiency of NADH can reach up to 95 % after 3 h of light reaction, which was about 1.6 times higher than that of the control group. Ultra-fast femtosecond time-resolved transient absorption (fs-TA) showed that Ce/TCPP-UiO-66-NH2 possessed the shortest average decay time (τ¯ = 1.12 ps), indicating shorter average life-time of carriers after Ce doping, thus suppressing hole-electron recombination. Finally, the key enzyme formate dehydrogenase (FDHPa) for CO2 activation was immobilized on the membrane, combining with light regeneration of NADH for CO2 production to formate. The formate yield (3.1 mM) was 16 times higher than that of the control group (0.19 mM). This work provided an effective strategy and efficient photocatalyst for the biomimetic photocatalytic activation of CO2 to formate, which is an indispensable bridge for the further high-valuable Cn compounds production by biocatalysis.

Effect of Ce codoping on the thermoluminescence dosimetry and photoluminescence behavior of SrBPO5:Dy/Sm/Eu

Effect of Ce on the thermoluminescence and photoluminescence of Dy, Sm and Eu in SrBPO5 was investigated. Samples of Sm, Dy, Eu doped and Ce-Dy/Sm/Eu codoped SrBPO5 were prepared through the high temperature solid-state synthesis route. Prepared phosphor samples were checked for their phase purity with powder X-ray diffraction analysis. Thermoluminescence glow curves were recorded for the phosphors and explored for the dosimetric applications. TL glow curves of 20 Gy gamma irradiated SBP:Dy0.01−1/Sm0.01−1/Eu0.01−1 and SBP:Ce1-Dy0.01−1/Sm0.01-Eu0.01−1 were obtained with 2 K/s heating rate. Gamma dose response of the phosphor samples were studied from 5 mGy to 100 Gy. The SBP:Ce1-Dy0.5 and SBP:Ce1-Sm1 demonstrated excellent dose linearity to gamma dose. The thermoluminescence behavior indicated that, Ce codoping has profound effect on the amount and type of traps and the glow peak intensity of Ce codoped SBP:Dy/Sm enhanced significantly. The photoluminescence study suggested efficient exchange type energy transfer interaction between excited states of Ce3+ and Dy3+/Sm3+ in the SrBPO5 host. The results confirmed the suitability of SBP:Ce-Dy/Sm phosphors for the thermoluminescence applications. The range of dose linearity of SBP:Ce-Dy, and SBP:Ce-Sm phosphor were found to be better than the commercial CaSO4:Dy and could be promising materials for personal as well as accidental dosimetry.

Light yield and thermal quenching of Ce3+ and Pr3+ co-doped LaBr3:Sm2+ near-infrared scintillators

LaBr3:Ce3+ is a compound with excellent scintillation properties, but its ultraviolet emission does not match well with the detection efficiency curves of silicon based photodetectors. In this work, Sm2+ is studied as an activator for LaBr3 as its near-infrared emission can be detected with close to 100% efficiency by such photodetectors. LaBr3:Sm2+ single crystals were grown with and without co-doping of Ce3+ or Pr3+. The samples were studied by means of X-ray excited and photoluminescence spectroscopy at temperatures between 10 K and 300 K. Their spectroscopic properties are compared to LaBr3:Ce3+ and LaBr3:Eu2+. The effect of using Ce3+ or Pr3+ as scintillation sensitiser for Sm2+ is assessed. It is found that energy transfer from host to Sm2+ greatly improves upon Ce3+ co-doping, but the quenching temperature of the Sm2+ emission decreases. The quenching mechanism of both the Ce3+ and Sm2+ emission in LaBr3 is elaborated on. Furthermore, the effect of charge compensating defects on the light yield and spectroscopic properties is discussed.

Fast Ce,Ca:LuAG scintillation ceramics for HEP: Fabrication, characterization, and computation

AbstractHigh‐energy physics community is looking for a hard, fast, and low‐cost scintillation material, and Ce:Lu3Al5O12 (Ce:LuAG) ceramic is one of the competitive candidates. This work presents Ce,Ca:LuAG scintillation ceramics with good optical quality, and the influence of Ce and Ca concentrations on optical and scintillation properties was fully analyzed. At relatively low level of Ce concentration, the less Ca2+ content is needed to achieve a significant intensity increase in fast scintillation component while maintaining a relatively high light yield (LY). The introduction of only 0.1 at% Ca2+ could increase the LY0.5 μs/LY3.0 μs from 79.9% to 96.1% in Ce,Ca:LuAG ceramics of 0.1 at% Ce. First‐principles investigations are further performed to reveal the tuning mechanisms of the scintillation properties of LuAG by Ce and Ca codoping. We show that the Fermi level shifts down with Ca codoping, which increases the Ce4+ content and decreases the depth of the electron traps (VO), resulting to a faster decay. Moreover, the formation preference of Ca‐VO complexes over Ce‐VO leads to the suppression of the non‐radiative decay of Ce via VO. In summary, our study demonstrates the realization of the performance tuning of LuAG via Ce and Ca codoping.

Influence of Sr and Ce Codoping on Structural, Electrical and Thermoelectric Properties of CaMnO3

Polycrystalline samples of CaMnO3 and Ca1-x-ySrxCeyMnO3 with Ce/Sr double substitution (x = 0.02, 0.04, 0.06; y = 0.02) were prepared by citrate sol-gel route. The samples’ phase was confirmed using the X-ray diffraction (XRD) technique, revealing that they only contain a single phase with an orthorhombic perovskite structure and no impurity phases. Also, the increase in lattice parameters with Sr2+ doping was observed. Rietveld refinement was done on the X-ray pattern using Fullprof software to find parameters. Using scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDS), analyses of morphology and elemental compositions were performed. On sintered samples, electrical resistivity measurements were made using DC four-probe techniques. And conduction mechanism was explained based on a small polaron hopping mechanism. Between 308 K and 673 K, thermoelectric characteristics were studied. Ca0.94Sr0.04Ce0.02MnO3 has the highest power factor of all the prepared co-doped Ce/Sr samples.

Cerium and carbon-sulfur codoped mesoporous TiO2 nanocomposites for boosting visible light photocatalytic activity

Ce and C–S codoped mesoporous TiO2 nanocomposites were synthesized via a sol-gel method integrated with an evaporation-induced self-assembly approach. The basic physicochemical characteristics of the synthetic samples were analyzed via a series of characterization techniques. The results reveal that C–S and Ce codoping on mesoporous TiO2 enhances the photocatalytic activity owing to the synergistic effect caused by narrowing the band gap, enhancing adsorption, trapping and transferring the excited e–/h+ pairs and suppressing the recombination of e–/h+ pairs. Furthermore, the obtained C,S–TiO2/CeO2 materials exhibit large specific surface areas and numerous pores which not only effectively improve the adsorption-enrichment capability, but also supply multi-dimensional mass and electron transfer channels. The photodegradation efficiency of RhB by C,S–TiO2/CeO2 within 40 min is nearly 100%, and its degradation efficiency is 6.63 times that of undoped TiO2. Recycling experiments show that mesoporous C,S–TiO2/CeO2 shows excellent recoverability and stability. Furthermore, by trapping experiments, •O2–, h+ and •OH are the predominant active species and a possible reaction mechanism is proposed.

Enhancement of luminescence, thermal stability and quantum efficiency with Ce3+ co-doped SrMg1·06Al9·94O17:Tb3+ phosphor

In this study, the photoluminescence properties of a series of SrMg1·06Al9·94O17 (SMAO):Ce3+, Tb3+, and SMAO:Tb3+ phosphors were investigated. At an excitation wavelength of 230 nm, the SMAO:Tb3+ phosphor emitted green light at 544 nm. When Ce3+ ions were co-doped into SMAO:Tb3+, the excitation band red-shifted from 230 to 269 nm, and the emission intensity was enhanced up to approximately 28 times compared with that of Ce3+-free SMAO:Tb3+ because of the efficient energy transfer from Ce3+ → Tb3+ in the SMAO host. Moreover, with the introduction of Ce3+, the thermal stability of the phosphors improved significantly. The luminescence intensity of the SMAO:3 mol%Tb3+ phosphor at 450 K was approximately 47% of that at room temperature. With the co-doping of Ce3+ ions, the emission intensity at 450 K was as high as 67%. The internal quantum efficiency (IQE) of SMAO:3 mol%Tb3+, 3 mol%Ce3+ increased to 55.14%. The SMAO:Tb3+,Ce3+ phosphors have potential applications in solid-state lighting.

Conductivity and transport number of Sc and Ce co-doped CaHfO3

CaZrO3-based proton conductors possess high transport numbers, and can thereby yield accurate Nernst concentration electromotive force. These features make them suitable for use in commercialized hydrogen sensors for gas and aluminum melts. Since CaHfO3-based proton conductors have higher transport numbers than CaZrO3, they are more suitable for the fabrication of electrochemical hydrogen sensors. Therefore, CaHf0.9Sc0.1O3 was employed in the present work as base material followed by further modification with Ce co-doping. Accordingly, CaHf0.9-xCexSc0.1O3-δ (x ​= ​0, 0.1, and 0.2) samples were prepared by solid-state reaction sintering process. Conductivities and transport properties of resulting materials were systematically investigated by AC-impedance spectroscopy and defect equilibria model. Standard molar hydration enthalpies of CaHf0.9-xCexSc0.1O3-δ (x ​= ​0, 0.1, and 0.2) were recorded as −61.1 ​kJ/mol, −59.3 ​kJ/mol, and −77.1 ​kJ/mol, respectively. Activation energies for conduction of protons, oxygen ions, and holes were estimated to be 0.56–0.77 ​eV, 1.15–1.26 ​eV, and 1.02–1.49 ​eV, respectively. Among the materials, CaHf0.8Ce0.1Sc0.1O3-δ displayed the highest protonic transport number reaching 0.961–0.512 under 2.5%H2O+21%O2 atmosphere. Overall, CaHf0.8Ce0.1Sc0.1O3-δ is promising for applications in electrochemical hydrogen sensors.