X-ray Photoelectron Spectroscopy Investigation Research Articles

Aminopropylimidazole as an Advantageous Coating in the Synthesis of Functionalized Magnetite Nanoparticles.

Implementing new methods to prepare magnetite nanoparticles with a covered or uncovered surface has been, and still is, a significant challenge. In this work, we describe a very clear and effortless way for the preparation of magnetite nanoparticles using two types of bases, namely: 1-(3-aminopropyl)imidazole and sodium hydroxide. Fourier transform infrared spectroscopy (FTIR) served as a tool for the structural investigation of the as-prepared magnetite nanoparticles. The morphology of the samples was investigated using Transmission Electron Microscopy (TEM). Comprehensive high-resolution X-ray photoelectron spectroscopy investigations (XPS) were applied as an effective tool for analyzing the composition of the various types of magnetic nanoparticles. Further polymer linkage was accomplished with poly(benzofuran-co-arylacetic acid) on the amino-functionalized surface of aminopropylimidazole-containing magnetic nanoparticles. The findings are promising for biomedicine, catalysis, and nanotechnology applications.

Optically sensitive isolated silver nano-dots development by broad ion implantation on nitrogen ion-induced pre-patterned silicon nano-templates

We report broad ion beam-induced isolated silver nano-dot formation on the pre-patterned silicon nitride nano template. The nano templates are developed and optimized on Si (100) surfaces using N2+ ion bombardment at different incidence angles and fluences. Atomic Force Microscopy shows that the well-defined pyramidal structures can be formed by 14 keV, N2 ion bombardment at incidence angle 70° with ion fluence 2 × 1018 ions/cm2. Optical sensitive, implanted Ag nano-dots are placed at selective sites of the patterns by exploiting the geometrical structure of the pattern and local ion implantation angle. Surface chemical analysis by X-ray photoelectron spectroscopy and cross-sectional investigation by transmission electron microscopy (TEM) confirms the presence of isolated Ag dots arrays at the specific sites of the nano-pyramidal template structures. The presence of isolated Ag dots on the silicon/silicon nitride surface shows a significant enhancement of the Raman signal, which further rises by the increase of Ag ion fluence. A change of light reflectance from the substrate surface is also observed due to the presence of Ag dots. The growth mechanism of the pyramidal structure by grazing incidence ion bombardment and the approach of isolated Ag dot formation by the self-masking process as well as optical responses are described.

Re-examination of the Aqueous Stability of Atomic Layer Deposited (ALD) Amorphous Alumina (Al2O3) Thin Films and the Use of a Postdeposition Air Plasma Anneal to Enhance Stability.

Amorphous aluminum oxide (alumina) thin films are of interest as inert chemical barriers for various applications. However, the existing literature on the aqueous stability of atomic layer deposited (ALD) amorphous alumina thin films remains incomplete and, in some cases, inconsistent. Because these films have a metastable amorphous structure─which is likely partially hydrated in the as-deposited state─hydration and degradation behavior likely deviate from what is expected for the equilibrium, crystalline Al2O3 phase. Deposition conditions and the aqueous solution composition (ion content) appear to influence the reactivity and stability of amorphous ALD alumina films, but a full understanding of why these alumina films hydrate, solvate, and/or dissolve in near-neutral pH = 7 conditions, for which crystalline Al2O3 is expected to be stable, remains unsolved. In this work, we conduct an extensive X-ray photoelectron spectroscopy investigation of the surface chemistry as a function of water immersion time to reveal the formation of oxyhydroxide (AlOOH), hydroxide (Al(OH)3), and possible carbonate species. We further show that brief postdeposition exposures of these ALD alumina films to an air plasma anneal can significantly enhance the film's stability in near-neutral pH aqueous conditions. The simplicity and effectiveness of this plasma treatment may provide a new alternative to thermal annealing and capping treatments typically used to promote aqueous stability of low-temperature ALD metal oxide barrier layers.

Corrosion Behavior of Chromium Coated Zy-4 Cladding under CANDU Primary Circuit Conditions

The manuscript is focused on corrosion behavior of a Cr coating under CANada Deuterium Uranium(CANDU) primary circuit conditions. The Cr coating is obtained via the thermionic vacuum arc procedure on Zircaloy -4 cladding. The surface coating characterization was performed using metallographic analysis and scanning electron microscopy (SEM) with an energy dispersive spectra detector (EDS), X-ray diffraction (XRD), and X-ray photoelectron spectroscopy (XPS) investigations. The thickness of the Cr coating determined from SEM images is around 500 nm layers After the autoclaving period, the thickness of the samples increased in time slowly. The kinetic of oxidation established a logarithmic oxidation law. The corrosion tests for various autoclaving periods of time include electrochemical impedance spectroscopy (EIS) and potentiodynamic tests, permitting computing porosity and efficiency of protection. All surface investigations sustain electrochemical results and promote the Cr coating on Zircaloy-4 alloy autoclaved for 3024 h as the best corrosion resistance based on decrease in corrosion current density values simultaneously with the increase of the time spent in autoclave. A slow increase of Vickers micro hardness was observed as a function of the autoclaved period as well. The value reached for 3024 h being 219 Kgf/mm2 compared with 210 Kgf/mm2 value before autoclaving.

Altering magnetic and optical features of rare earth orthoferrite LuFeO3 ceramics via substitution of Ir into Fe sites

LuFeO3 and LuFe1-xIrxO3 ceramics with x ​= ​0.05 and 0.10 have been obtained by solid-state reaction process. Scanning electron microscope (SEM) analyses have revealed the existence of both particle agglomeration and porosity of nature of the studied samples. The X-ray photoelectron spectroscopy (XPS) investigations have revealed that while Lu has 3+, Fe has mix valence states, 2+ and 3+. On the other hand, the Ir dopant has metallic and 4+ valence states in the study samples. The Raman investigations unveiled i) the Raman peak intensity reduces with Ir doping until ∼600 ​cm−1, ii) the peaks appearing between 200 ​cm−1 and 600 ​cm−1 wavenumbers shift toward the smaller values. Magnetic measurements, conducted by vibrating sample magnetometer (VSM), have shown the spin re-orientation (SR) transition temperature around 47 ​K for all the investigated samples. Furthermore, it is noticed the 5 ​mol % Ir doped sample has higher magnetization than other samples owing to existence of magnetic impurities such as Lu3Fe5O12. M ​− ​H loops have unveiled that Ir doping advances both Hc and Mr values compared to the undoped LFO sample. This increase in both Hc and Mr values could be due to 1) the variation of the canted angels of Fe3+ moments, 2) the advancement of energy of magnetocrystalline anisotropy, and 3) formation of secondary phases such as Lu3Fe5O12 and Fe3O4. Furthermore, the optical band gap examinations have revealed that the band gap of LFO reduces from 2.19 ​eV to 2.

Matching the Cellulose/Silica Films Surface Properties for Design of Biomaterials That Modulate Extracellular Matrix.

The surface properties of composite films are important to know for many applications from the industrial domain to the medical domain. The physical and chemical characteristics of film/membrane surfaces are totally different from those of the bulk due to the surface segregation of the low surface energy components. Thus, the surfaces of cellulose acetate/silica composite films are analyzed in order to obtain information on the morphology, topography and wettability through atomic force microscopy (AFM), X-ray photoelectron spectroscopy (XPS) and contact angle investigations. The studied composite films present different surface properties depending on the tetraethyl orthosilicate (TEOS) content from the casting solutions. Up to a content of 1.5 wt.% TEOS, the surface roughness and hydrophobicity increase, after which there is a decrease in these parameters. This behavior suggests that up to a critical amount of TEOS, the results are influenced by the morphology and topographical features, after which a major role seems to be played by surface chemistry—increasing the oxygenation surfaces. The morphological and chemical details and also the hydrophobicity/hydrophilicity characteristics are discussed in the attempt to design biological surfaces with optimal wettability properties and possibility of application in tissue engineering.

The fabrication and characterization of half-Heusler YPdBi thin films

The electrical, optical, and magnetic properties of half-Heusler compounds make them novel interesting materials being studied by many groups worldwide. The synthesis of YPdBi, a member of half-Heusler compounds, thin films have been achieved at different deposition temperatures such as 360 °C and 470 °C by employing magnetron co-sputtering technique. X-ray diffraction (XRD) examinations have revealed that the film deposited at 360 °C has a slightly larger lattice parameter, 6.82 Å, than the film fabricated at 470 °C, having 6.73 Å. The induced strain of the films has been 2.1% and 0.7% for the films deposited at 360 °C and 470 °C, respectively. X-ray photoelectron spectroscopy (XPS) investigations have revealed the obtained films have the stoichiometry close to the 1:1:1 ratio. Scanning electron microscopy (SEM) studies have shown that surface topography varies dramatically as the deposition temperature advances. Furthermore, high-resolution scanning transmission electron microscopy (STEM) has shown that layer-plus-island growth known as the Stranski–Krastanov (SK) growth mode, taking place due to minimization of strain energy, leads to the island formation from a specific film thickness on. It has been shown that while the resistance of the sample grown at 470 °C changes abruptly at 2.45 K, which indicates the onset of superconductivity, the sample deposited at 360 °C does not show this effect. The absence of the onset of superconductivity in this latter case might be associated with the lattice strain and intensive scattering in this sample.

Multifunctional feature of double perovskite strontium iron vanadate for storage device

In this report, we have investigated the structure, vibration, optical, dielectric, transport and magnetic features of the double perovskite Sr2FeVO6. The structural investigation of the sample is done by incorporating X-ray diffraction (XRD) and scanning electron microscopic (SEM) technique at room temperature. The structural investigation suggests the formation of a single phase polycrystalline sample having monoclinic symmetry. The chemical composition and valence of the involved elements are investigated by incorporating the X-ray photoelectron spectroscopic (XPS) technique. The dual oxidation state of Fe is revealed through the XPS investigation. The vibrational property of the sample is analyzed through both Raman and FTIR spectroscopic methods. The various modes of vibrations such as symmetric, anti-symmetric and bending modes are illustrated through Raman and FTIR techniques. Analysis of optical spectrum and energy bandgap of the sample is done by UV–Visible spectroscopic technique. The bandgap (Eg = 2.88 eV) of the material is found suitable for photocatalytic activities. The dielectric spectrum of the sample is analyzed by investigating the variation of dielectric parameters, that is εr and tanδ, w.r.t frequency-temperature. The dielectric spectrum is found consistent with Maxwell-Wagner model. The electrical and transport activities in the material are investigated by analyzing the spectra of impedance, modulus and AC conductivity at varying frequencies and temperatures. The relaxation feature of the material is illustrated through impedance and modulus spectroscopic techniques whereas the significant contribution of hopping conduction mechanism is depicted through AC conductivity spectra. Finally, the ferromagnetic property of the material at room temperature is clarified through the hysteresis curve.

Raman and X-ray photoelectron spectroscopic investigation of solution processed Alq3/ZnO hybrid thin films

In this study, we characterize the solution processed tris-(8-hydroxyquinoline)aluminum(Alq3)/ZnO hybrid thin films using Raman and X-ray photoelectron spectroscopic (XPS) techniques. Raman studies reveal the sol–gel derived spin-coated ZnO thin film has hexagonal wurtzite structure. The incorporation of Alq3 molecules in the hybrid film results in the formation of bonding onto the surface of highly crystalline ZnO nanoparticles. The XPS confirms the incorporation of Alq3 in the hybrid thin films and corroborates that the Alq3 molecules may be adsorbed onto the surface of ZnO nanoparticles (chemisorption), showing the existence of chemical interaction between Alq3 and ZnO in the hybrid films. These studies support that the chemisorbed Alq3 molecules onto the ZnO nanoparticles may facilitate the charge transfer (non-radiative) between Alq3 and ZnO in the hybrid thin films which will be useful to enhance the optical and electrical properties for the optoelectronic device applications.

Ultrafine PdRu Nanoparticles Immobilized in Metal–Organic Frameworks for Efficient Fluorophenol Hydrodefluorination under Mild Aqueous Conditions

Ultrafine PdRu Nanoparticles Immobilized in Metal–Organic Frameworks for Efficient Fluorophenol Hydrodefluorination under Mild Aqueous Conditions

Hard/soft effects of multivalence co-dopants in correlation with their location in PZT ceramics

Piezoelectric hard/soft effects of multivalence co-dopants (Sb and Mn) in correlation with their location in the lattice, were investigated in PZT ceramics, prepared by conventional ceramic technology, with the following compositions: Pb0.98Sr0.02 ((Ti0.49Zr0.51)1-0.015-xMn0.015Sbx)O3 with x = 0, 0.005, 0.01, 0.02, 0.03, where antimony was initially assumed to substitute for Ti/Zr ions. The antimony valence state was found to be +3 in all samples by X-ray Photoelectron Spectroscopy investigations. The Electron Paramagnetic Resonance spectra evidenced a steep enhancement of the Mn2+ concentration upon increasing antimony doping level, explained by a charge compensation mechanism, between the Sb3+ ions substituting Pb2+ at the A-sites and the Mn2+ ions, localized at the B-sites. The incorporation of Sb3+ at the A-site of the PZT lattice is also supported by the variation of the lattice parameters, determined by X-ray Diffraction, with the increasing Sb concentration. The investigation of the dielectric, electromechanical and ferroelectric properties evidenced a hard piezoelectric behavior, mainly attributed to the presence of large sized Mn2+ ions, localized at B-sites. Our results prove that the piezoelectric hard/soft response is decisively influenced by the interplay between multiple valence states and locations of the co-dopants, on one hand, and the charge compensation mechanisms, on the other hand. This provides indirect information about the location of some co-dopants which can substitute for both cationic sites in the PZT based ceramics.

Boosting Efficient Ammonia Synthesis over Atomically Dispersed Co-Based Catalyst via the Modulation of Geometric and Electronic Structures

Boosting Efficient Ammonia Synthesis over Atomically Dispersed Co-Based Catalyst via the Modulation of Geometric and Electronic Structures

Iodine local environment in high pressure borosilicate glasses: An X-ray photoelectron spectroscopy and X-ray absorption spectroscopy investigation

• Iodine is dissolved as iodide (I − ) in high pressure borosilicate glasses. • Both alkali and alkaline-earth cations act as a charge compensator to I − species. • The absence of iodate (I 5+ ) suggests that there is a complex interplay between I − species and oxygen species within the glass structure. The 129 I radioactive isotope is a by-product of nuclear plants activity. Owing to its strong volatility, there is currently no ideal protocol to immobilize 129 I in nuclear waste borosilicate glasses. Recently, we have proposed the use of high-pressure syntheses to dissolve iodine in various glass compositions; however, I speciation and dissolution mechanism could not be determined. We have adopted an approach combining X-ray Photoelectron Spectroscopy (XPS) and X-ray Absorption Spectroscopy (XAS) methods to determine I speciation and molecular environment in glasses containing from 0.5 to 2.5 mol.% I. The XPS spectra reveal that I is mostly dissolved as iodide (>85% I − ) with a small proportion of elemental iodine (<15% I 0 ) and the absence of iodate species (I 5+ ). For borosilicate glasses, the XAS results and subsequent spectrum simulations suggested that Na and Ca are involved in the I − vicinity with averaged derived coordination number (CN) of 3.6 and 2.0 and bond length to the nearest neighbour (r X-I ) 2.98 and 2.85 Å, respectively. These results suggest that the coexistence of both I − and I 5+ species is not requested for electric neutrality but instead, we explain the I speciation by the possible interplay with oxygen species from the borosilicate matrix. In addition, the results imply that the borosilicate network is affected by the I dissolution.

Study of the electronic structure of Ce0.95Fe0.05O2-δ thin film using X-ray photoelectron spectroscopy

In the present work, the effect of the oxygen partial pressure (OPP) has been studied on the electronic structure of the Ce0.95Fe0.05O2-δ thin film (TF) through Raman spectroscopy, atomic force microscopy (AFM), and X-ray photoelectron spectroscopy (XPS). The varying OPP, from 200 mTorr to 1 mTorr, was observed to vary the oxidation conditions during TF deposition. The oxygen valency was estimated to be reduced along with the generation of oxygen vacancies as determined via Raman analysis. The AFM analysis revealed the lowered values of the roughness parameters which indicated that reduction in OPP is associated with the smoothness of the film surface. The film surface was found to be reduced, as characterized by XPS investigation, as a result of the change in valency of Ce from +4 to +3 due to reduced OPP. The concentration of Ce3+ state was estimated to increase from 19.5% to 33% with reducing OPP. This evidently supports the formation of oxygen vacancies since the reduction of the valence state of Ce is known to be accompanied by the generation of oxygen vacancies. The O1 s spectra confirmed the oxygen non-stoichiometry as a function of OPP, whereas, Fe 2p suggested the mixed-valence state of Fe (Fe2+/Fe3+) in Ce0.95Fe0.05O2-δ (TF). To put in brief, the variation in OPP affects the chemical composition of the material by modifying its electronic structure via controlling the exchange interactions in the core structure of the compound.

Effects of Surface Heterogeneity of α-Quartz and α-Cristobalite on Adsorption of Crystal Violet

Silica minerals are a kind of important minerals and widespread on the earth’s surface. They play an irreplaceable role in the whole geochemistry and environment processes. The diversity in the crystal structure of SiO2 polymorphs might lead to the heterogeneity in their surface microstructures and properties. As two common SiO2 polymorph minerals in soil and sediments, α-quartz and α-cristobalite have been studied for the effects of their surface heterogeneity on adsorption behaviors toward crystal violet (CV) by batch adsorption experiments in different specific surface areas (SSAs) and at different pH values and temperatures, as well as by X-ray photoelectron spectroscopy (XPS) investigation. Owing to the larger surface site density, the saturated adsorption amount of α-quartz was larger than that of α-cristobalite. It was also indicated by the larger slope of adsorption lines as a function of SSA. The adsorption capacity of both increased with increasing pH and temperature. In the thermodynamic study, the negative ΔG indicated that the adsorption of CV on the surface was spontaneous and the positive ΔH suggested that the reaction was endothermic. The well-fitted Langmuir adsorption isotherms suggested that the CV adsorption was monolayer adsorption. The adsorption interaction force was mainly involved in electrostatic attraction force between the negatively charged surface reactive sites and positively charged N atoms in the dimethylamino groups of CV. The XPS spectra of N 1s showed that the stoichiometric ratio of Nlow/Nhigh changed from lower than 2:1 to about 2:1 as the adsorption changed from the unsaturated to saturated state. The change reflected that the spatial arrangement of adsorbed CV monomer on the mineral surface could be readjusted by lifting the average tilt angle between the average plane of the CV monomer and the sample surface during the adsorption process. Surface heterogeneity of α-quartz and α-cristobalite controlled the different distributions and postures of adsorbed CV monomers on the surface. The CV monomers adsorbed on α-quartz presented a larger average tilt angle because of its larger surface reactive site density, while α-cristobalite did conversely.

Novel yellow light emission from vanadyl ions-doped calcium-lithium hydroxyapatite nanopowders: structural, optical, and photoluminescence properties

Phosphor luminescent materials, especially those activated with transition metal ions, have been extensively investigated during the last decade because of their potential in various applications such as displays, medical imaging, lighting, and fluorescent lamps. In this study, a mechanochemical approach was used for the synthesis of novel yellow light-emitting vanadyl ion (VO2+)-doped calcium-lithium hydroxyapatite (CLHA) nanophosphors. The structural, morphological, optical, photoluminescence, and chromaticity properties of the as-prepared nanopowders were systematically examined. Phase structural analysis showed that the as-prepared samples were highly crystalline and corresponded to the hexagonal crystal phase of hydroxyapatite. X-ray photoelectron spectroscopy investigation indicated the existence of elements. The spectroscopic results indicate that the doped VO2+ ions belong to the tetragonally distorted octahedral site symmetry. The chromaticity results show that the chromaticity coordinates (x, y) for the VO2+-doped CLHA nanopowders were (0.448, 0.401), (0.430, 0.384), and (0.423, 0.377). The emission colors are positioned in the orange, orange-yellow, and pale-yellow regions, respectively, for VO2+-doped CLHA nanopowders. Thus, the light emission properties shift from orange to yellow as the dopant concentration increases from 0.01 to 0.05 mol%. These results demonstrate that phosphor materials doped with transition metal ions are suitable for display device applications.

Heterometallic Clusters with Multiple Rare Earth Metal-Transition Metal Bonding.

Although a series of complexes with rare earth (RE) metal-metal bonds have been reported, complexes which have multiple RE-Rh bonds are unknown. Here we present the identification of the first example of a molecule containing multiple RE-Rh bonds. The complex with multiple Ce-Rh bonds was synthesized by the reduction of a d-f heterometallic molecular cluster Ce{N[(CH2CH2NPiPr2)RhCl(COD)]3} with excess potassium-graphite. The oxidation state of Ce in 3a appears to be a mixture of Ce(III) and Ce(IV), which was confirmed by X-ray photoelectron spectroscopy, magnetism, and theoretical investigations (DFT and CASSCF). For comparison, the analogous species with multiple La(III)-Rh and Nd(III)-Rh bonds were also constructed. This study provides a possible route for the construction of complexes with multiple RE metal-metal bonds and an investigation of their potential properties and applications.

In situ XPS investigation of the X-ray-triggered decomposition of perovskites in ultrahigh vacuum condition

X-ray photoelectron spectroscopy (XPS) has been used to investigate the composition of perovskite films upon exposure to different environmental factors, such as moisture, heat, and UV light. However, few research studies have determined that the X-ray itself could cause damage to the perovskite crystals. In this study, the X-ray-induced degradation of CH3NH3PbI3 perovskite films was investigated via XPS within an in situ ultrahigh vacuum system. It is demonstrated that fresh methylammonium lead iodine contains Pb2+ without the initial existence of Pb0. The Pb0 signal was discovered after a few hours of soft X-ray exposure, which indicates that the CH3NH3PbI3 perovskite structure undergoes a decomposition process to form metallic Pb. In addition, the nitrogen content was found to be significantly decreasing in the first hour of X-ray exposure. The discovery of the X-ray-induced chemical state change and the volatile methylamine of perovskite crystals could be further applied as an indicator for the field of X-ray sensors or detectors.

Thermally Stimulated Wettability Transformations on One-Cycle Atomic Layer Deposition-Coated Cellulosic Paper: Applications for Droplet Manipulation and Heat Patterned Paper Fluidics.

Cellulosic materials are widely used in daily life for paper products and clothing as well as for emerging applications in sustainable packaging and inexpensive medical diagnostics. Cellulose has a high density of hydroxyl groups that create strong intra- and interfiber hydrogen bonding. These abundant hydroxyl groups also make cellulose superhydrophilic. Schemes for hydrophobization and spatially selective hydrophobization of cellulosic materials can expand the application space for cellulose. Cellulose is often hydrophobized through wet chemistry surface modification methods. This work reports a new modification method using a combination of atomic layer deposition (ALD) and atmospheric heating to alter the wettability of purely cellulosic chromatography paper. We find that once the cellulosic paper is coated with a single ALD cycle (1cy-ALD) of Al2O3, it can be made sticky superhydrophobic after a 150 °C ambient post-ALD heating step. An X-ray photoelectron spectroscopy investigation reveals that the ALD-modified cellulosic surface becomes more susceptible to adsorption of adventitious carbon upon heating than an untreated cellulosic surface. This conclusion is further supported by the ability to use alternating air plasma and heat treatments to reversibly transition between the hydrophilic and hydrophobic states. We attribute the apparent abruptness of this wetting transition to a Cassie-Wenzel-like phenomenon, which is also consistent with the sticky hydrophobic wetting behavior. Using scanning probe methods, we show that the surfaces have roughness at multiple length scales. Using a Cassie-Wenzel model, we show how a small change in the surface's Young's contact angle-upon adsorption of adventitious carbon-can lead to an abrupt increase in hydrophobicity for surfaces with such roughnesses. Finally, we demonstrate the ability to spatially pattern the wettability on these 1cy-ALD-treated cellulosic papers via selective heating. This ALD-treated hydrophobic paper also shows promise for microliter droplet manipulation and patterned lab-on-paper devices.

Insights into the adsorption mechanism of tannic acid by a green synthesized nano-hydroxyapatite and its effect on aqueous Cu(II) removal.

The polyphenolic tannic acid (TA) has been widely used in the stabilization and surface modification of nanomaterials. The interaction mechanism of TA with the biogenic nano-hydroxyapatite (nHAP) and its environmental importance, however, are poorly understood. This study explored the adsorption of TA using the green synthesized, eggshell-derived nHAP and implications of this process for the removal of aqueous Cu(II) via batch adsorption experiments, Raman spectroscopy, Fourier transform infrared spectroscopy (FTIR), and X-ray photoelectron spectroscopy (XPS) investigations. TA adsorption by nHAP was a complex pH-dependent process and significantly correlated with TA molecule speciation and amphoteric properties of nHAP via multiple adsorption modes including surface complexation, electrostatic attraction, and hydrogen bond. The maximum TA adsorption amount was found to be 94.8mg/g for less crystalline nHAP with lower calcination temperature. In the ternary Cu-TA-nHAP systems, TA promoted Cu(II) adsorption at pH<5 and reduced Cu(II) uptake at pH>5. Further studies of the effects of ionic strength and addition sequences, as well as Raman, FTIR, and XPS analyses revealed Cu(II) adsorption on nHAP was mainly dominated by inner-sphere surface complexation. These results can shed light on not only the utility of biogenic nHAP for TA and Cu(II) adsorption but also the evaluation of the effect of TA on the environmental behavior of heavy metals.