Energy Difference Research Articles

Energetics and Structural Transitions of Nonequivalent Polytypes for FCC and HCP Metals

AbstractAlthough metal nanomaterials with unconventional phases have attracted extensive attention, the lack of information on the characteristics of metal polytypes hinders the development of related research. In this work, the energetics of nonequivalent polytypes for bulk face‐centered cubic (Li, Al, Ca, Cu, Sr, Rh, Pd, Ag, Ir, Pt, Au, and Pb) and hexagonal close‐packed metals (Be, Na, Mg, Sc, Ti, Zn, Cd, Y, Zr, Tc, Ru, Hf, Re, Os, and Tl) is systematically reported. For each metal, the structural properties and energies for its polytypes with up to the periodic stacking length of L = 10 is obtained by DFT calculation. The variation tendency of the energy differences between 3C and 2H polytypes is summarized in the Periodic Table of Elements. Generally, the ratio c/(La) increases when metal crystals except Ir, Rh, Zn, and Cd leave away from their ground‐state structure. It is found that the energy difference between polytypes originates from various interactions between the two types of atomic layers: the k layer and the h layer. The work is helpful to understand not only the structural transitions in bulk metals, such as Li, Na, Sr, Ti, Al, Pb, Y, Re, and Tl, but also the evolutions of Au nanomaterials.

Single-crystal growth, crystal structure, and molecular dynamics of organic–inorganic [NH3(CH2)2NH3]CuBr4

As part of obtaining excellent properties that can be used as lead-free hybrid solar cells, the crystal growth, crystal structure, phase transition temperature, and thermal properties for [NH3(CH2)2NH3]CuBr4 were discussed. The crystal structure at 300 K was determined to be monoclinic by single-crystal X-ray diffraction (XRD) analysis. The phase transition temperatures were determined to be 447 and 473 K, and the results were consistent with the powder XRD patterns. Thermogravimetric analysis revealed thermal stability up to ~ 460 K. The continuous changes in the 1H and 13C chemical shifts and 14N static resonance frequency with increasing temperature are related to variations in the local environment and coordination geometry. The significant differences in activation energies obtained from the 1H and 13C spin–lattice relaxation times (t1ρ) at low and high temperatures were discussed. The activation energy results suggested that the energy barrier at low temperatures was related to the reorientation of the NH3 and CH2 groups around the three-fold symmetry axis, and the energy barrier at high temperatures was related to the reorientation of the [NH3(CH2)2NH3] cation. These physical properties will be provide important insights or potential applications of this crystal.Please check and confirm that the corresponding author and their respective corresponding affiliation have been correctly identified and amend if necessary.OK !

Structures and stabilities Ru-doped Agn (n = 1–13) clusters: Ag10Ru a 18-ve cluster superatom

The geometrical and stability properties of Ru-doped silver clusters (AgnRu with n = 1–13) are investigated by density functional theory (DFT) calculations. The results show that the Ru dopant adopts central positions in the lowest-energy structures of AgnRu clusters. The most stable structures found are planar and curved for n = 3–6, while for n = 6 onward the structures follow a pentagonal growth pattern. Interestingly for n = 10, we found a cage structure with fulfills the 18 electron rule. The relative stability of the clusters is further evaluated through energetic parameters such as ionization energy, electron affinity, second order energy difference and HOMO–LUMO gap. The results show that the most stable structures in this series are Ag3Ru, Ag6Ru and Ag10Ru, as supported by electronic structure analyses. The plausible formation of the Ag10Ru cluster as a superatomic species is rationalized with 1.64 eV of HOMO–LUMO gap and 6.23 eV of adiabatic ionization energy.

The electric double layer structure and interface energy of uranium electrode in molten LiCl-KCl-UCl3 mixture: A molecular dynamics simulation study

The electric double layer structure and interface energy of uranium electrode in molten LiCl-KCl-UCl3 mixture, as well as the surface energies of metallic uranium and molten salts, were investigated using molecular dynamics simulations. The surface energies were calculated, respectively, from the pressure tensor and the energy difference for molten salt and uranium, and interface energy was evaluated from the Gibbs free energy difference between systems with and without interface. The surface energies of molten alkali halides are between 76.4 and 201.8 mJ·m−2 and decrease with the increase of radius of the halide anion or the alkali cation for molten salt with the same alkali cation or the same halide anion. The surface energy of uranium depends on the allotrope morphology and crystal facet, and the surface energies of α-U, β-U, and γ-U are 2.36, 1.45, and 1.69 J·m−2 in average for the seven low index crystal facets. The interface energy of uranium and molten LiCl-KCl-UCl3 mixture is about 2.71 J·m−2 and increases with the increase of charge density on the uranium slabs. The molten LiCl-KCl-UCl3 mixture in anodic zone has higher coordination number than that in cathodic zone but similar coordination distance.

Quantifying Aspect‐Dependent Snowpack Response to High‐Elevation Wildfire in the Southern Rocky Mountains

AbstractIncreasing wildfire frequency and severity in high‐elevation seasonal snow zones presents a considerable water resource management challenge across the western United States (U.S.). Wildfires can affect snowpack accumulation and melt patterns, altering the quantity and timing of runoff. While prior research has shown that wildfire generally increases snow melt rates and advances snow disappearance dates, uncertainties remain regarding variations across complex terrain and the energy balance between burned and unburned areas. Utilizing paired in situ data sources within the 2020 Cameron Peak burn area on the Front Range of Colorado, U.S., during the 2021–2022 winter, we found no significant difference in peak snow water equivalent (SWE) magnitude between burned and unburned areas. However, the burned south aspect reached peak SWE 22 days earlier than burned north. During the ablation period, burned south melt rates were 71% faster than unburned south melt rates, whereas burned north melt rates were 94% faster than unburned north aspects. Snow disappeared 7–11 days earlier in burned areas than unburned areas. Net energy differences at the burned and unburned weather station sites were seasonally variable, the burned area snowpack lost more net energy during the winter, but gained more net energy during the spring. Increased incoming shortwave radiation at the burned site was 6x more impactful in altering the net shortwave radiation balance than the decline in surface albedo. These findings emphasize the need for post‐wildfire water resource planning that accounts for aspect‐dependent differences in energy and mass balance to accurately predict snowpack storage and runoff timing.

Microscopic insights into effects of sulfolane additive on Li-S battery electrolyte

Lithium–sulfur (Li-S) batteries, which have a high theoretical capacity and can be prepared using low-cost activation materials, are a promising alternative for realizing high-energy–density battery systems. However, the stability of the electrolyte and the shuttle effect caused by dissolved lithium polysulfides in the electrolyte prevent their practical application. Due to its non-flammability and high oxidation stability, sulfolane shows good promise for improving the oxidation stablility and weakening the shuttle effect of Li-S electrolytes. In this work, the effects of a sulfolane additive on a Li-S battery electrolyte were revealed by density functional theory calculations and molecular dynamics simulations. The molecular orbitals, thermodynamics, and dynamics of the oxidation reaction were analyzed from the electron level. The addition of sulfolane lowers the HOMO energy level and the configuration energy difference, which leads to improved oxidation stability. Furthermore, sulfolane shows affinity to the S atoms close to Li, which correspond to low-order polysulfides. This affinity is confirmed by binding energy data and indicates that the addition of sulfolane inhibits the diffusion of Li2S4, Li2S6 and Li2S8. This work provides an analysis of the effects of sulfolane as an additive from the electron and molecular levels, which will promote a better understanding of Li-S battery systems and enable the design of improved electrolytes.

Uncovering a Genetic Diagnosis in a Pediatric Patient by Whole Exome Sequencing: A Modeling Investigation in Wiedemann–Steiner Syndrome

Background: Wiedemann–Steiner syndrome (WSS), a rare autosomal-dominant disorder caused by haploinsufficiency of the KMT2A gene product, is part of a group of disorders called chromatinopathies. Chromatinopathies are neurodevelopmental disorders caused by mutations affecting the proteins responsible for chromatin remodeling and transcriptional regulation. The resulting gene expression dysregulation mediates the onset of a series of clinical features such as developmental delay, intellectual disability, facial dysmorphism, and behavioral disorders. Aim of the Study: The aim of this study was to investigate a 10-year-old girl who presented with clinical features suggestive of WSS. Methods: Clinical and genetic investigations were performed. Whole exome sequencing (WES) was used for genetic testing, performed using Illumina technology. The bidirectional capillary Sanger resequencing technique was used in accordance with standard methodology to validate a mutation discovered by WES in all family members who were available. Utilizing computational protein modeling for structural and functional studies as well as in silico pathogenicity prediction models, the effect of the mutation was examined. Results: WES identified a de novo heterozygous missense variant in the KMT2A gene KMT2A(NM_001197104.2): c.3451C>G, p.(Arg1151Gly), absent in the gnomAD database. The variant was classified as Likely Pathogenetic (LP) according to the ACMG criteria and was predicted to affect the CXXC-type zinc finger domain functionality of the protein. Modeling of the resulting protein structure suggested that this variant changes the protein flexibility due to a variation in the Gibbs free energy and in the vibrational entropy energy difference between the wild-type and mutated domain, resulting in an alteration of the DNA binding affinity. Conclusions: A novel and de novo mutation discovered by the NGS approach, enhancing the mutation spectrum in the KMT2A gene, was characterized and associated with WSS. This novel KMT2A gene variant is suggested to modify the CXXC-type zinc finger domain functionality by affecting protein flexibility and DNA binding.

Probing room temperature indirect and minimum direct band gaps of h-BN

Hexagonal boron nitride (h-BN) has attracted considerable interest as an ultrawide bandgap (UWBG) semiconductor. Experimental studies focused on the detailed near band-edge structure of h-BN at room temperature are still lacking. We report a direct experimental measurement of the near band-edge structure performed on h-BN quasi-bulk wafers via photocurrent excitation spectroscopy (PES). PES resolved the band-to-band transitions near M- and K-points in the Brillion zone (BZ), from which the room temperature indirect band gap of EgMK ∼6.02 eV, minimum direct bandgap at M-point of EgM=6.36eV and next lowest direct energy bandgap at K-point of EgK=6.56eV, have been simultaneously determined for the first time experimentally. The measured energy differences between K- and M-points in the conduction band minimum (CBM) and valence band maximum (VBM) are Δ ECMK=0.54eV and Δ EVMK = 0.34 eV, respectively, in good agreement with the calculation results. Significantly differing from its III-nitride wurtzite counterparts, in which only electrons and holes in the conduction and valence band extremes at the Γ-point are predominantly involved in the optical and transport processes, the results highlighted that charge carriers associated with both M- and K-valleys control to the optical excitation, recombination and charge transport processes in h-BN.

Investigation of the Effect of Herbal Omega-3-Rich Food Consumption on Hematologic Parameters and Total Cholesterol Levels According to Physical Activity Status in Healthy Individuals

Objective: It is known that walnut consumption has favorable effects on health. Walnuts are known to be a food rich in unsaturated fatty acids and herbal omega-3 fatty acids. This study investigated the effects of walnut (plant omega-3) consumption on hematologic factors in healthy adults with a certain physical activity level. Methods: Healthy participants in this study were offered thirty grams of walnuts per day for three weeks. Walnuts were consumed on an empty stomach or with breakfast every morning for three weeks. The blood values of people were measured at the beginning and the end of the study. Hematological parameters were measured in the routine blood test from blood taken. Results: The effect of a consumption rich in vegetable omega-3 products on hematologic factor levels caused a significant difference in MCH (p=0.001), MCHC (p=0.001) and LENFOSIT (p=0.001) levels. A significant increase in HCT levels was found only in male subjects. No significant changes were observed in other hematologic parameters. In addition, although a decrease in TC levels (p=0.023) and an increase in MONOSITE levels (p=0.027) were observed after consumption of plant omega-3 in active individuals, this difference was not observed in sedentary individuals. On the other hand, sedentary individuals showed an increase in LENFOSITE levels after consumption of plant-based omega-3 (p=0.016), whereas this difference was not observed in active individuals. There was also a statistically significant difference in carbohydrate, PUFA and a-linolenic acid intake compared to TBSA. There were no significant differences in energy, cholesterol, monounsaturated fatty acid and saturated fatty acid intakes. Conclusion: In this study, the addition of plant omega-3 fatty acids to the diet of healthy volunteers affected some hematologic factors and is thought to have a stimulating effect against cells that defend the body. It was also observed that the effect on hematologic factors and cholesterol levels was higher when plant omega-3 supplements were given to individuals who engaged in regular physical activity. We think that the effect of plant omega-3 fatty acids on hematologic factors should be further investigated.

Establishment of a 241Am gamma calibration field based on international standards and its conversion coefficients.

A 241Am gamma (γ)-ray calibration field that meets the requirements for a γ-ray reference field as specified in the ISO 4037 standard series was established in the Facility of Radiation Standards of the Japan Atomic Energy Agency. The reference air kerma rates were measured using a reference ionization chamber calibrated by the N-80 quality X-ray calibration field of the national metrology standard in Japan and with a correction to account for differences in photon energy due to the calibration field. Conversion coefficients for the 241Am γ-ray calibration field, including those not listed in the ISO 4037 standard series, were calculated based on the measured γ-ray fluence rate spectra.

Optimal scheduling of green heating systems in buildings considering economy and exergy efficiency

Green heating in buildings is of great significance to global energy conservation and emission reduction, and the design of optimal scheduling models is the key to achieve cost reduction and efficiency improvement in heating systems. For the building heating system containing multiple heterogeneous energy sources such as solar energy, air energy and electricity, a multi-objective optimal scheduling model is established with the goal of maximizing the exergy efficiency and minimizing the economic cost of the system, taking into account the quality difference of energy in the conversion process. Regarding the nonconvex and nonlinear constraints in the scheduling model, the incremental linearization method and Big-M method are used to linearize the transformation, and obtain the multi-objective mixed-integer linear programming model. Further, the ε-constraint method is used to solve the Pareto frontier of multi-objective optimization and the technique for order preference by similarity to ideal solution (TOPSIS) method is used to make decision. Finally, the simulation study of the model is carried out, and the results show that the proposed multi-objective optimal scheduling can balance the system operation economy and exergy efficiency compared with the belief rule base and evidential reasoning (BRB-ER) method, and the system’s daily economic cost are reduced by 9.66 %, 9.94 % and 17.24 %, respectively, and the system’s average daily coefficient of performance (COP) are improved by 4.66 %, 14.05 % and 13.22 %, respectively, on three typical days, it is verified that the proposed optimal scheduling model has better economy and exergy efficiency. The proposed multi-objective optimal scheduling model introduces exergy efficiency rather than energy efficiency as one of the optimization objectives of the heating system and reasonably solves the optimization model, which can provide a new idea and reference for the multi-objective optimal scheduling of the green heating system in buildings.

Spectroscopic, anti-cancer, anti-bacterial and theoretical studies of new bivalent Schiff base complexes derived from 4-bromo-2,6-dichloroaniline

In this paper, four new mono-nuclear Ni(II), Pd(II), Pt(II) and Zn(II) complexes were prepared by using a bi-dentate Schiff base ligand, (E)-2-(((4-bromo-2,6-dichlorophenyl)imino)methyl)-5-chlorophenol (BrcOH), with bivalent ions in a methanol and distil water mixture as solvent in presence of NaOH as base. The structures of the prepared compounds were characterized by spectroscopic techniques (IR and 1H NMR), CHN analysis, and molar conductivity. The M(II) (Ni, Pd and Pt) ions are four-coordinated by a bi-dentate N2O2 donor ligand, forming square planar geometry, whereas the Zn(II) is coordinated as a tetrahedral geometry. The newly synthesized compounds, which include the Schiff base ligand and its complexes, underwent antibacterial screening against E. coli and S. aureus. The results demonstrated a remarkable and noteworthy biological activity of these compounds against these pathogenic bacterial strains. Different binding energies showed good correlation, with Pd showing the strongest binding. Small energy differences indicated high reactivity, with Ni and Pd complexes being the most reactive. Electrophilicity index exhibited electron-accepting properties, with Zn showing the highest reactivity. The dipole moments showed polarity and charge separation, with Pt having the highest polarity. We evaluated the pharmacokinetic properties (ADME) of a ligand and its metal complexes using the Swiss ADME website. The results of the in-silico prediction of physicochemical properties revealed that ten compounds in total adhered to Lipinski's rule.

Phosphor-doping modulates the d-band center of Fe atoms in Fe-N4 catalytic sites to boost the activity of oxygen reduction

Regulating the electronic structure by phosphor-doping is a preferred strategy to boost the performance of carbon-based catalysts for oxygen reduction reaction (ORR). Here, a porous Fe, P, N-codoped carbon catalyst (PCF-FeTz-900) is designed by a phytic acid-assisted thermal etching strategy, in which P atoms are first doped into the carbon matrix to form a stable PC bond, and then FeN4 sites are produced from Fe-2,4,6-Tris(2-pyridyl)-s-triazine complex (Fe-TPTz). Theoretical calculations suggest that the electrons are transferred from the doped P atom to the neighboring FeN4 sites, which facilitates the ORR at the Fe sites by reducing the energy barrier and the adsorption energy of intermediates. Additionally, the P-doped FeN4 (FeN4P) structure manifests a lower free energy difference than that of FeN4 and the d-band center of Fe is also lowered, which further ensures its higher ORR catalytic ability. As a result, the PCF-FeTz-900 catalyst exhibits superior ORR activity and stability in alkaline electrolyte, and the assembled primary zinc-air battery shows greater performances compared to the commercial Pt/C catalyst. This work can provide an effective pathway for modulating the performance of doped-carbon materials in energy conversion devices.

Spread and spectral complexity in quantum spin chains: from integrability to chaos

We explore spread and spectral complexity in quantum systems that exhibit a transition from integrability to chaos, namely the mixed-field Ising model and the next-to-nearest-neighbor deformation of the Heisenberg XXZ spin chain. We corroborate the observation that the presence of a peak in spread complexity before its saturation, is a characteristic feature in chaotic systems. We find that, in general, the saturation value of spread complexity post-peak depends not only on the spectral statistics of the Hamiltonian, but also on the specific state. However, there appears to be a maximal universal bound determined by the symmetries and dimension of the Hamiltonian, which is realized by the thermofield double state (TFD) at infinite temperature. We also find that the time scales at which the spread complexity and spectral form factor change their behaviour agree with each other and are independent of the chaotic properties of the systems. In the case of spectral complexity, we identify that the key factor determining its saturation value and timescale in chaotic systems is given by minimum energy difference in the theory’s spectrum. This explains observations made in the literature regarding its earlier saturation in chaotic systems compared to their integrable counterparts. We conclude by discussing the properties of the TFD which, we conjecture, make it suitable for probing signatures of chaos in quantum many-body systems.

Quasi-equilibrium growth of inch-scale single-crystal monolayer α-In2Se3 on fluor-phlogopite

Epitaxial growth of two-dimensional (2D) materials with uniform orientation has been previously realized by introducing a small binding energy difference between the two locally most stable orientations. However, this small energy difference can be easily disturbed by uncontrollable dynamics during the growth process, limiting its practical applications. Herein, we propose a quasi-equilibrium growth (QEG) strategy to synthesize inch-scale monolayer α-In2Se3 single crystals, a semiconductor with ferroelectric properties, on fluor-phlogopite substrates. The QEG facilitates the discrimination of small differences in binding energy between the two locally most stable orientations, realizing robust single-orientation epitaxy within a broad growth window. Thus, single-crystal α-In2Se3 film can be epitaxially grown on fluor-phlogopite, the cleavage surface atomic layer of which has the same 3-fold rotational symmetry with α-In2Se3. The resulting crystalline quality enables high electron mobility up to 117.2 cm2 V−1 s−1 in α-In2Se3 ferroelectric field-effect transistors, exhibiting reliable nonvolatile memory performance with long retention time and robust cycling endurance. In brief, the developed QEG method provides a route for preparing larger-area single-crystal 2D materials and a promising opportunity for applications of 2D ferroelectric devices and nanoelectronics.

Exploration of deep UV-NLO responses of non-conjugated crystal systems by harnessing aprotic solvents: DFT vs experimental

This study introduces a newly found form of a non-conjugated crystal called 1,3,5-triazine-2,4,6-triamine polymorph (TT), which demonstrates a well-rounded UV nonlinear optical (NLO) behavior. By employing solvent-assisted Tauc bandgap adjustment, the crystal's structure was altered, leading to improved optical characteristics. The material's monoclinic polymorph displays adjustable bandgaps that are impacted by the choice of solvent during the crystallization process. When evaluated against a chemical potential of −2.61 eV, its characteristics were forecasted. Charge displacement across the aromatic ring is observed in the solvent stage, while molecular electrostatic potential (MEP) surfaces highlighted the nitrogen atoms as nucleophilic. The comparative examination of its energy gaps (Egaps) offers significant perspectives on their prospective uses. Understanding these energy differences is crucial for choosing materials for specific applications like electronic devices, sensors, or catalysis. Moreover, comprehending charge distributions and nucleophilic tendencies can influence the creation of new materials with customized attributes for diverse uses in fields such as chemistry, materials science, and beyond.

Unusual C-N coupling mechanism via NO dimerization for the electrochemical synthesis of urea on transition metal dimers supported by two-dimensional expanded phthalocyanine

Electro-synthesis of urea is a powerful alternative to traditional demanding industrial engineering by selective reduction of N2 and CO2. Due to the existence of inert NN bond, usual C-N coupling has always hindered the design and performance of catalysts. Herein, we present an unusual C-N coupling mechanism for highly electrochemical catalytic synthesis of urea via NO dimerization on transition metal dimers supported by two-dimensional expanded phthalocyanine (TMTM-Pc) as a prototype through first principles calculations. The key is that the adsorbed *NO dimer can directly jump over challenging step of N-N bond breaking and associate with CO. Particularly, FeFe-Pc is singled out in terms of activity, selectivity, and stability via proposed reaction pathways. What's more, we discovered an easy descriptor, namely, the difference of the adsorption energies of *NO-CO-NO* and *NO-NO*, ∆E(*NO-CO-NO* - *NO-NO*), to consummately depict the thermal-kinetic relationships for the C-N coupling. This work may broaden the understanding of urea formation mechanism and provide more options for future research.

Exchange-correlation potential built on the derivative discontinuity of electron density.

Electronic structures are fully determined by the exchange-correlation (XC) potential. In this work, we develop a new method to construct reliable XC potentials by properly mixing the exact exchange and the local density approximation potentials in real space. The spatially dependent mixing parameter is derived based on the derivative discontinuity of electron density and is first-principle. We derived the equations for solving the mixing parameter and proposed an approximation to simplify these equations. Based on this approximation, this new method gives reasonable predictions for the ionization energies, fundamental gaps, and singlet-triplet energy differences for various molecular systems. The impact of the approximation on the constructed XC potentials is examined, and it is found that the quality of the XC potentials can be further improved by removing the approximation. This work demonstrates that the derivative discontinuity of electron density is a promising constraint for constructing high-quality XC potentials.

Controllably hydrolytic dehydrogenation of NH3BH3 over micropore-dominant porous carbon confined RuPd ultrafine alloys

At present, controllable producing hydrogen from the catalytic hydrolysis of ammonia borane (AB, NH3BH3) is very meaningful and challenging. Therefore, developing an effective catalyst for the reaction, clarifying its catalytic mechanism, and realizing controllable hydrogen release are extremely indispensable. In this work, RuPd nanoalloys are evenly confined by the agricultural waste wheat straw-derived carbon (denoted as WSC) with a micropore-dominant porous structure and plentiful N/O doping. Attributing to the particular support effect of WSC and the interesting RuPd alloy effect, the as-prepared bimetallic catalysts provide encouraging catalytic performance in AB hydrolysis. Catalyzed by the optimal Ru0.50Pd0.50@WSC, the turnover frequency (TOF) and hydrogen evolution rate are 214.5 min−1 and 50800 mL min−1 g−1, respectively, and the apparent activation energy is only 23.2 kJ mol−1. Moreover, introducing proper NaOH (1.5 M) further accelerates hydrogen release (TOF = 502.8 min−1, specific rate = 119100 mL min−1 g−1). The isotope experiments depict a kinetic isotope effect of 2.85, evidencing the vital role of the hydrogen–oxygen bond scission in this catalytic reaction. More importantly, benefitting from the difference in adsorption energy and strong coordination ability, the “on–off” control for the hydrolysis of AB over Ru0.50Pd0.50@WSC can be realized with the Zn2+/EDTA2- system. This study provides an attractive metal alloy catalyst and some insights for the controllable hydrolysis of AB.

Effects of Nd-doping on crystal phase, structure and photocatalytic performance of TiO2 powders prepared by sol-gel method

Abstract In this work, 0.3–2 mol% neodymium (Nd) doped titanium dioxide (TiO2) powder was prepared by sol–gel method. The XRD showed that the anatase phase occur for the Nd doped TiO2 powders, and the Nd doping suppressed the original rutile phase for the pure TiO2 powder. SEM and TEM revealed that Nd doping reduced the tendency of severe aggregation and increased the specific surface area compare with pure TiO2 powder, and the Gibbs free energy difference did not reach the critical value of the phase transition driving force, while the adjustment of the Ti-O bond length caused by the addition of Nd3+ impeded the transformation of TiO2 to rutile phase. The photocatalytic activity test results for Methylene blue show that the 0.5 mol% Nd doped TiO2 had the best photocatalytic activity with the degradation efficiency of 96.2%.