Dysprosium Oxide Research Articles

Photocatalytic activity and radiation-attenuation ability of copper ions surface-doped dysprosium oxide

Photocatalytic activity and radiation-attenuation ability of copper ions surface-doped dysprosium oxide

Enhancement of dysprosium oxide doped zinc alumino borosilicate glasses in thermal, optical and luminescence domain for solid state lighting application

Zinc alumino borosilicate (ZABS) glasses incorporated with Dy3+ ions are prepared through melt-quenching technique. Non-crystallinity behaviour of the glasses are confirmed through XRD studies. The presence of functional and vibrational groups in the glass network are witnessed through FTIR studies. From the differential thermal analysis (DTA), the thermal stability of the glasses are found to be greater than 90 °C. UV–Visible–NIR spectra of glasses showed strong absorptions of Dy3+ ions in the NIR region (∼1267 nm). The highest bandgap value is obtained for ZABSDy0.5 (4.27 eV) glass that has the lowest amount of non-bridging oxygens. The ionic nature of dysprosium ions in the glass vicinity is thereby known through bonding parameter calculation. Judd-Ofelt (J-O) intensity parameters showed the trend Ω2 > Ω6 > Ω4, maintained same for all synthesized glasses. The luminescence spectra showed three emission peaks of Dy3+ ions at 482 (6H15/2), 575 (6H13/2) and 663 (6H11/2) nm. The hypersensitive transition observed at 4F9/2 → 6H13/2 exhibits a greater emission cross-section and radiative transition for all the glasses. Through the decay measurements, the lifetime of the Dy3+ ions are calculated. The estimated CIE coordinates for the glasses showed their location in white light region. The correlated colour temperature (CCT) values are obtained between 4200 and 4500 K suggesting the importance of glasses to use for white-LEDs application.

Biosynthesis of Dy2O3 nanoparticles using Piper Retrofractum Vahl extract: Optical, structural, morphological, and photocatalytic properties

Biosynthesis of nanoparticles has attracted much attention due to its environmental safety, cost-effectiveness, and straightforward fabrication. For the first time, Piper Retrofractum Vahl Fruits Extract (PRFE) was used as a low-cost natural hydrolyzing agent in the synthesis of Dysprosium Oxide (Dy2O3). The optical, structural, morphological, and photocatalytic properties of Dy2O3 nanoparticles were observed by various characterization methods such as FT-IR, XRD, UV-Vis DRS, FESEM-EDS, and TEM. The absorption bands of the C-N and N-H functional groups were revealed by FT-IR analysis. Alkaloid compounds of PRFE are assigned to the hydrolyzing agents. Furthermore, the XRD and EDS analyses confirmed the presence of Dy2O3 without impurities. Morphological characterization by FESEM showed that Dy2O3 nanoparticles were in a spherical shape, while the particles size was obtained to be 20-30 nm validated by TEM measurement. The optical bandgap of Dy2O3 was 4.8 eV, which is active in the UV region. Dy2O3 nanoparticles showed a remarkable photocatalytic activity, which has an efficiency of 92.76%, with a small amount of catalyst loading for malachite green degradation under UV light irradiation within 120 min. The trapping experiment proved that h+ is the predominant reactive species in the photodegradation reaction. Ultimatelly, this work presents a superior biosynthesized Dy2O3 photocatalyst, which demonstrates high stability in four consecutive cycles.

Hydrogenation of CO2 over Cobalt‐Lanthanide Bimetallic Oxide Nanofibers

AbstractCobalt‐lanthanide bimetallic oxide nanofibers (5Co3O4.3LnCoO3, Ln=La, Pr; 4Co3O4.Ln2O3, Ln=Sm, Gd, Dy, Yb and 2Co3O4.CeO2) were prepared by electrospinning technique and for the first time evaluated as catalysts for the hydrogenation of CO2. Depending on the lanthanide, the reaction products are different: lighter lanthanides (La, Pr, Sm and Gd) produce mainly CO and are more active to reverse water gas shift (RWGS), whereas the catalysts with Ce, Dy and Yb are more active and selective to methane. Lanthanide intrinsic properties such as ionic radii and basicity strongly correlate with the nanofibers’ catalytic performance: lower lanthanide ionic radii and higher basicity favour the catalysts activity. Moreover, the bimetallic oxide nanofibers catalytic behavior also seems to point to the existence of a synergetic interaction between cobalt and lanthanide. The cobalt‐lanthanide bimetallic oxides present a high deactivation resistance for at least 60 h in the gaseous stream, which is an advantage for any catalytic application. Compared with a commercial catalyst (5wt.% Rh/Al2O3) tested in the same conditions, cobalt‐ytterbium, dysprosium and cerium bimetallic oxide nanofibers present an activity 5 to 13 times higher at 350 °C.

Sinter‐Crystallization and Optical Characterization of Dy 3+ : ZnO‐B 2 O 3 ‐RHA Glass‐Ceramics

In this current study, the behavior of dysprosium oxide (Dy2O3) doped willemite glass-ceramic (WGC) derived from ZnO-B2O3-RHA: Dy2O3 glasses and rice-husk ash (RHA) works as the active alternative silica has been studied. The fusions of the ternary host system of oxide components doped with rare earth oxide go through the melt-quench technique followed by solid-state sintering on the compacted glass frits. The sintered green samples are characterized utilizing the physical, structural, and optical properties to investigate the effect of different sintering temperatures on the samples accordingly. The bulk density of WGC increases together with the increment of sintering temperature from 2.571 to 2.940 g cm–3. Meanwhile, the increment of sintering temperature escalates the crystallization of the main crystalline phase, Zn2SiO4, corroborated by the enlargement of average crystallite size from 161 to 550 nm. Furthermore, the emission activity in the WGC also intensifies on the green emission region (524 nm) accordingly. This fabricated Dy3+:WGC contributes to the nomination as the potential solid-state lighting material.

Physical and luminescence properties of zinc barium gadolinium borate glass doped with dysprosium oxide for white light emission

Zinc barium gadolinium borate glass samples with the compositions 10ZnO: 15BaO: (74.5x) B2O3: 0.5Dy2O3: xGd2O3 while (x: 0, 2, 4, 6, 8 and 10 mol%) were prepared by normal melt quenching technique at 1,200 °C for 1.5 h. The melts were annealed in the oven at 350 °C for another 3 h. The physical and luminescence properties were investigated. The density, molar volume and refractive index are increasing with the concentration of Gadolinium oxide. The absorbance spectra measured in the range of 200 – 2,500 nm, show the peaks at 797, 901, 1082, 1262 and 1680 nm corresponding to the energy transitions from the ground state 6H15/2 to the excited states 6F5/2, 6F7/2, (6F9/2, 6H7/2), (6F11/2,6H9/2) nanometres respectively. The spectra have been used to derive the Judd-Ofelt (J-O) parameters (Ωλ, λ = 2, 4 and 6). The trend of J-O parameters is Ω2 > Ω4 > Ω6. It was found that the emission at 576 nm can be excited by the light from Gd3+ of 275 nm. Excited with the light of 275 nm, the emission peak was found at 576 nm corresponding to the transition from 4F9/2 to 6H13/2 with the highest intensity at 6 mol% of Gadolinium oxide. The calculation results located in the CIE 1931 chromaticity diagram, shows that the composited light emitted from the sample is cool white.

Study of Densification Behavior of SiAlONs Using Dysprosium Containing Additive System

SiAlON ceramics have complicated chemistry and should be considered a group of alloys with diverse characteristics. It is generated when silicon nitride (Si3N4), aluminium oxide (Al2O3) and aluminium nitride (AlN) react together. If sintering aids such as Dysprosium oxide are added to the initial composition, fully dense polycrystalline bodies can be produced through pressureless sintering.Inter-granular phase composition and structure may be modified by dopants and sintering conditions, which significantly impact the characteristics of SiAlON ceramics. The focus of this study was concentrated on the nature of densification and nature of the phases that appeared in SiAlON. It was found that the volume and density of all the specimens considerably reduced and enhanced, respectively owing to sintering at elevated temperatures. The XRD results showed various phases as per their relative intensities, which indicates densification will alter different properties, especially mechanical and thermal properties.

ZnO Doped Lanthanide Oxide Nanomaterials as Photocatalysts for Selective Organic Transformation Reactions: Synthesis of N- Phenyl-P-Benzoquinonimine

Heterogeneous semiconductor nanomaterials are widely employed nowadays as efficient photocatalysts for selective organic transformation reactions. A co-precipitation technique was employed for the preparation of ZnO doped dysprosium oxide from the respectivemetal nitrates and characterization studies were conductedby FT-IR, X-Ray Differaction, UV-Visible-DRS and FE-SEM analysis. XRD showed the prepared nanomaterial to be in a nano range with high crystallinity. The particles possesed a spherical morphology and of the order of 40-50 nm(particle size) as evidenced from FE-SEM analysis. From theUV-Visible-DRS analysis the band gap energy was calculated as 3.15 eV. The synthesizedZnO doped dysprosium oxide was employed as a photocatalyst under UV light irradiation for selective organic transformation reaction. Quinones especially benzoquinones are a class of compounds which forms a basic structural skeleton for various natural compounds. They are widely employed asa precursor for natural products synthesis. Herein we report the synthesis of N-phenyl-p-benzoquinonimine from diphenylamine by employing ZnO doped dysprosium oxide as a photocatalyst under UV light irradiation in ethanol. Thin Layer Chromatography was used to check the progress of the reaction. Optimization studies for the reaction parameters were conducted systematically.

Study on the fluorination of dysprosium oxide by ammonium bifluoride for the preparation of dysprosium fluoride

In this report, dysprosium fluoride (DyF3) - a material for the preparation of dysprosium (Dy) metal was prepared by the fluorination of dysprosium oxide (Dy2O3) by ammonium bifluoride (NH4HF2) reagent. The effect of reaction time and temperature on the formation of dysprosium fluoride salt has been studied. The phase composition and crystal structure of the obtained products were analysed by X-ray diffraction (XRD). Thermal analysis techniques were applied to determine the temperature range of the fluorination. Scanning electron microscopy with energy dispersive spectroscopy (SEM/EDS) was used for external morphology observation and chemical elemental composition analysis. The results showed that the high purity phase of DyF3 was formed at the conditions: reaction time and temperature of >1 h and >350oC, respectively. The product is available for the preparation of Dy metal by metallothermic reduction.

Development of a Dy2O3@Eu2O3-carbon nanofiber based electrode for highly sensitive detection of papaverine

A sensitive electrochemical method based on carbon nanofibers (CNFs) and bimetallic nanoparticles of dysprosium oxide (Dy2O3) and europium oxide (Eu2O3) was developed for the determination of papaverine in pharmaceuticals and human urine. Several electrodes were compared in respect to their electrochemically active surface area calculated as 0.0603, 0.1300, 0.3440, 0.3740 and 0.4990 cm2 for bare GCE, CNFs/GCE, Eu2O3-CNFs/GCE, Dy2O3-CNFs/GCE and Dy2O3@Eu2O3-CNFs/GCE, respectively. Electrodes were also compared in respect to their performance towards the voltammetric process of papaverine. The peak potential (Epa) of papaverine was 1.094 V, 0.993 V, 0.978 V, 0.969 V and 0.966 V at unmodified GCE, CNFs/GCE, Eu2O3-CNFs/GCE, Dy2O3-CNFs/GCE and Dy2O3@Eu2O3-CNFs/GCE, respectively. This indicated that the oxidation peak potential of papaverine shifted gradually towards the negative potentials and the peak current increased gradually from unmodified GCE to CNFs/GCE, Eu2O3-CNFs/GCE, Dy2O3-CNFs/GCE and Dy2O3@Eu2O3-CNFs/GCE. The influence of experimental parameters such as scan rate and pH on the voltammetry of papaverine was studied. The Dy2O3@Eu2O3-CNFs/GCE system presented a dynamic working range between 1.0 × 10−7 and 2.0 × 10−6 M with a detection limit of 1.0 × 10−8 M for papaverine. The platform (Dy2O3@Eu2O3-CNFs/GCE) exhibited excellent sensitivity and selectivity for papaverine in the presence of uric acid and was successfully applied for determining papaverine in pharmaceuticals and urine samples.

Modeling the Optical Properties of a Polyvinyl Alcohol-Based Composite Using a Particle Swarm Optimized Support Vector Regression Algorithm.

We developed particle swarm optimization-based support vector regression (PSVR) and ordinary linear regression (OLR) models for estimating the refractive index (n) and energy gap (E) of a polyvinyl alcohol composite. The n-PSVR model, which can estimate the refractive index of a polyvinyl alcohol composite using the energy gap as a descriptor, performed better than the n-OLR model in terms of root mean square error (RMSE) and mean absolute error (MAE) metrics. The E-PSVR model, which can predict the energy gap of a polyvinyl alcohol composite using its refractive index descriptor, outperformed the E-OLR model, which uses similar descriptor based on several performance measuring metrics. The n-PSVR and E-PSVR models were used to investigate the influences of sodium-based dysprosium oxide and benzoxazinone derivatives on the energy gaps of a polyvinyl alcohol polymer composite. The results agreed well with the measured values. The models had low mean absolute percentage errors after validation with external data. The precision demonstrated by these predictive models will enhance the tailoring of the optical properties of polyvinyl alcohol composites for the desired applications. Costs and experimental difficulties will be reduced.

Zinc-lead-borate glasses doped with dysprosium oxide: Structure, optical, and radiation shielding features

40PbO + 20ZnO + (40-x) B2O3 + xDy2O3 (where x = 0, 1, 2, 3, 4 and 5 wt%) glass samples were created via a traditional melt-quenching technique. The degree of structural compactness and the amendment of configurations in the glass network was verified by determining glass density. The linear optical properties of the samples were investigated by measuring U-V optical absorption over a spectral range of 190–900 nm. Both direct and indirect band gaps were found to decrease when the samples were doped with Dy2O3. The Urbach energy (Eu) yields increase as the number of doping materials in the samples increases. The gamma-ray shielding capacity of the samples was evaluated using MCNP-5 code. The simulated data found that the highest linear attenuation coefficient was obtained at 0.015 MeV. This attenuation varied between 2.84.43 and 346.33 cm−1 as the ratio of Dy2O3 rose from 0 to 5 wt%, respectively. Shielding factors like the half-value layer, the radiation protection efficiency and the transmission factor increased as more Dy2O3 was introduced.

Development of a wireless feeding system for highly effective electro-photocatalytic degradation of organic pollutants from aqueous solutions

In this study, we presented a novel wireless electro-photocatalytic (WEPC) process for the degradation of an industrial model dye RO29. The wireless electrochemical configuration consists of two titanium mesh sheets as feeder electrodes feeding an anodic bipolar electrode coated with Dysprosium (III) Oxide (Dy2O3)/graphite/Titanium oxide (TiO2) electro-photocatalytic. It was shown that this electrode arrangement can greatly boost electro-photocatalytic activity by lowering the recombination rate of electron/hole (e/h+) in the electro-photocatalytic, resulting in the rapid production of oxidizing species (•OH, O•). The experimental parameters such as potential gradient, initial pH, and reaction time were optimized to produce the best degradation performance based on chemical oxygen demand (COD) data. Under optimal conditions, a decolorization efficiency and degradation efficiency were found of 98% and 65%, respectively reached in 120 minutes, which is significantly greater than that of a standard two-electrode setup (75%, and 25%). The results also revealed that the percent degradation for developed and conventional systems is 65% and 29%, respectively. The results also showed that RO29 decay has quasi-first-order kinetics. The created WEPC is a simple setup with significant advantages such as high degradation performance, high energy efficiency, and the ability to operate without the use of supporting electrolytes and oxidation additives.

Graphene oxide-metal oxide nanocomposites for on-target enrichment and analysis of phosphorylated biomolecules.

The surface of matrix-assisted laser desorption/ionization mass spectrometry target is modified for improved signal strength and detection of analytes. The developed method includes on-target enrichment and detection of phosphopeptides/phospholipids using graphene oxide-lanthanide metal oxides (samarium, gadolinium, dysprosium, and erbium) nanocomposites. Enriched phosphopeptides are detected using material enhanced laser desorption/ionization mass spectrometry and phospholipids by laser desorption/ionization-mass spectrometry. Nanocomposites are prepared using graphene oxide with respective metal salts at high pH. They are characterized for nano-morphology, chemistry, porosity, composition, crystallinity, and thermal stability. Phosphopeptides enrichment protocol is developed and optimized for tryptic β-casein digest and that of phospholipids by phosphatidylcholine standard. Statistical analyses of phosphopeptides and phospholipids from milk show overlapping results for gadolinium, dysprosium, and erbium oxide nanocomposites. GO-Gd2 O3 has better enrichment efficiency and application as LDI material. Selectivity for GO-Dy2 O3 is 1:2500, for GO-Sm2 O3 is 1:3500, and 1:4000 for GO-Gd2 O3 . GO-Er2 O3 has a sensitivity of 25 fmol, whereas the highest sensitivity is down to 0.5 fmol for GO-Gd2 O3 . On-target enrichment is batch to batch reproducible with a standard deviation of<1, reduced time of enrichment to 10min, and ease of operation compared to solid-phase batch extraction. The developed method enriches serum phosphopeptides characteristic of cancer-related phosphoproteins.

Magneto-optical properties of borophosphate glasses co-doped with [formula omitted] and [formula omitted]ions

Glasses from lithium-aluminum-zinc-boron-phosphorous oxide system co-doped with terbium (Tb3+) and dysprosium (Dy3+) oxides were studied for magneto-optical applications in lasers. The Fourier Transform Infrared and Raman Spectroscopy complementary analysis suggested the depolymerization of the boro-phosphate glass network by adding and increasing the rare-earth (RE) oxide content. Main UV–vis absorption maxima of Tb and Dy ions were identified at 348 and 1266 nm. Spectroscopic ellipsometry indicated a maximum refractive index of 1.56, at 400 nm, for the highest RE content. The Verdet constant amplified by increasing the RE content, reaching for the 9 mol% RE co-doped sample a value of -0.075 min/Oe/cm at 630 nm. The Faraday rotation angle was additionally confirmed by using a Faraday Cell Device, being also related to the specific paramagnetic behavior evidenced by Superconducting Quantum Interference Device magnetometry. The magneto-optical properties recommend such vitreous co-doped materials for magneto-optical devices.

Electrochemical treatment of spent NdFeB magnet in organic acid for recovery of rare earths and other metal values

The spent Neodymium-Iron–Boron (NdFeB) magnet is potential secondary resource of rare earth elements. Conventional hydrometallurgical processing of spent NdFeB magnet requires energy intensive steps viz. crushing, grinding, roasting etc. and is associated with the discharge of acidic effluents in the environment. The chemical dissolution of waste magnet using biodegradable organic acids is also associated with the major drawback of poor leaching efficiency. The present study is focused on the electrochemical dissolution of spent NdFeB magnet in organic acid for the recovery of rare earths and other metal values. The electrochemical dissolution studies were carried out using citric acid as an electrolyte. The dissolution of spent NdFeB magnet in citric acid was studied with and without electrochemical effect. It was found that the dissolution of NdFeB magnet in citric acid enhanced significantly under electrochemical effect as compared to chemical dissolution. The reaction mechanism of electrochemical dissolution was also determined. The effect of various parameters such as citric acid concentration, current density, stirring speed, bath temperature etc. were studied for electrochemical dissolution of spent NdFeB magnet. The anodic dissolution efficiency and energy consumption were also evaluated. A solvent extraction method using 1M di-(2-ethylhexyl) phosphoric acid (D2EHPA) as an extractant was developed to extract rare earths selectively and quantitatively from the electrolytic liquor. From the loaded organic, mixed oxalates of rare earths were recovered quantitatively by precipitation stripping using oxalic acid solution as stripping agent. Mixed oxides of neodymium, praseodymium and dysprosium of purity 99.9% were obtained by calcination at 1073 K. Iron oxide (98.6% pure) was also produced as by-product of the process. The solid products were characterized by chemical analysis, XRD, SEM and TG-DTA. Enhanced dissolution of metals in citric acid under electrochemical effect is the main advantage of this electrochemical process. The developed process is clean and avoids energy intensive steps viz. crushing, grinding and roasting.

Intergrain connectivity in YBa2Cu3O7-δ superconductor added with Dy2O3 nanoparticles: AC susceptibility investigation

YBa2Cu3O7-δ (or YBCO) superconductors added with various concentrations of dysprosium oxide nanoparticles (NP-Dy2O3) were prepared using the solid-state process. The additive NP-Dy2O3 has a size of about 10 nm and presents a para/ferromagnetic transition at about 300 K. The characterization of samples was probed via XRD, TEM, SEM, DC magnetization, and AC susceptibility measurements. Some models were employed to compute superconducting parameters like intragranular critical current density under a magnetic field (Jcm(H)), the density of intragranular pinning force for Abrikosov vortex (εg(0)), intergranular critical current density (Jc,inter), intergranular electrical character, superconductor grain volume fraction (fs). The correlation between these parameters and microstructure was discussed. The inclusion of NP-Dy2O3 does not alter the structural properties and the spatial growth of YBa2Cu3O7-δ. NP-Dy2O3 addition led to significant enhancements of Jcm(H) and εg(0). The decrement in Jc,inter was attributed to the change of grain boundary characteristics that transformed from SNS to SINS junction due to NP-Dy2O3 addition.

Structure and spectroscopic ellipsometry studies of nanocrystalline Dy2O3 thin films deposited on Al2O3 wafers by electron beam evaporation technique

This work investigates the effect of film thickness on the optical properties of dysprosium oxide (Dy2O3), fabricated onto sapphire (Al2O3) substrates using electron beam evaporation. The grazing incidence X-ray diffraction (GI-XRD) analysis showed that all films have a cubic crystalline structure. The average crystallite size was calculated using the Debye–Scherrer equation and was found to increase with the increasing film thickness. Similar behavior was observed in scanning electron microscopy and atomic force microscopy images. The optical properties of the grown layers such as the refractive index (n), extinction coefficient (k), and optical allowed f–f transitions of Dy3+were analyzed using spectroscopic ellipsometry (SE). The allowed f–f transitions of Dy3+was found to increase from 2.35 eV to 2.50 eV by decreasing the film thickness from 10 nm to 5 nm. UV–Vis spectrophotometry was used to examine the reflectance of Dy2O3 thin films. The results obtained in this study indicated that Dy2O3 with a 5 nm thickness is a better choice to grow an improved anti-reflective layer compared with the 10 nm layer.

Linear/nonlinear optical parameters along with photon attenuation effectiveness of Dy3+ ions doped zinc-aluminoborosilicate glasses

In this study linear/nonlinear optical and γ-photon attenuation competences of dysprosium oxide (Dy3+ ions) doped zinc-aluminoborosilicate glasses based on (40−x) B2O3—20SiO2 –10Al2O3 –20NaF—10ZnO—xDy2O3, (where x = 0, 0.1, 0.5, 1.0. 1.5, 2.0 and 2.5 mol%) were investigated. Different types of calculation methods along with Monte Carlo simulations were used for determination of linear/nonlinear optical and γ-photon attenuation competences. Both molar refractivity (Rmolar) and molar polarizability (α molar) decreased as Dy3+ ions concentration increased. The optical transmission (Toptical) of the investigated glasses varied inversely to their reflection loss (Rloss). The obtained values of metallization criterion (Mcriterion) quantity showed that the studied glasses are insulator materials. The results also showed that Dy2.5 sample with the highest amount of Dy2O3 additive has the highest mass attenuation coefficients (μ m) and effective atomic number (Zeff) values. On the other hand, Half (HVL) and tenth (TVL) value layers were reported as (HVL, TVL)Dy0.0 > (HVL, TVL)Dy0.1 > (HVL, TVL)Dy0.5 > (HVL, TVL)Dy1.0 > (HVL, TVL)Dy1.5 (HVL, TVL)Dy2.0 > (HVL, TVL)Dy2.5. The maximum and minimum values of exposure and energy absorption buildup factors (EBF and EABF) were reported for Dy0.0 and Dy2.5 samples, respectively. It can be concluded that studied glasses are candidate materials for optical fibers and photonic devices. It can be also concluded that Dy2.5 sample is the superior sample in terms of gamma-ray attenuation competences.

Heterocyclic-Additive-Activated Dinuclear Dysprosium Electrocatalysts for Heterogeneous Water Oxidation.

Heterogeneous catalysis based on air-stable lanthanide complexes is relatively rare, especially for electrochemical water oxidation and reduction. Therefore, it is highly desired to investigate the synergy caused by cocatalysts on the lanthanide complex family for heterogeneous catalysis because of their structural diversity, air/moisture insensitivity, and easy preparation under an air atmosphere. Two mononuclear and three dinuclear dysprosium complexes containing a series of Schiff-base ligands have been demonstrated as robust electrocatalysts for triggering heterogeneous water oxidation in alkaline solution, in which the complex [Dy2(hmb)2(OAc)4]·MeCN(3) was revealed to have the best activity toward heterogeneous water oxidation among all five complexes in the present study. The molecular activation of dysprosium complexes has also been investigated with a series of N-containing heterocyclic additives [i.e., 4-(dimethylamino)pyridine (DMAP), bis(triphenylphosphine)iminium chloride ([PPN]Cl), indole, and quinoline]. In particular, the corresponding overpotential was effectively enhanced by 211 mV (at a current density of 10 mA cm-2) with the assistance of DMAP. On the basis of electrochemical and ex situ/in situ spectroscopic investigations, the best catalyst, DMAP-complex 3 on a carbon paper electrode, was confirmed with well-maintained molecular identity during heterogeneous water oxidation free of forming any dysprosium oxide and/or undesired products.