Investigation of a memory effect in a Au/(Ti–Cu)Ox-gradient thin film/TiAlV structure

• Damian Wojcieszak,
• Jarosław Domaradzki,
• Michał Mazur,
• Tomasz Kotwica and
• Danuta Kaczmarek

Beilstein J. Nanotechnol. 2022, 13, 265–273, doi:10.3762/bjnano.13.21

• also investigated to show the gradient distribution of Ti and Cu as a function of the thin film depth. X-ray photoelectron spectroscopy (XPS) studies were performed to determine the chemical state of titanium and copper on the surface of the mixed oxide thin films. A Specs XR-50 X-ray non-monochromatic

• energies of the spectra were referred to the Fermi level (EF) determined from a cleaned reference Au sample. Measurement results were analyzed with the aid of CasaXPS software. In the case of XPS and UPS measurements, the results were averaged over a certain surface area, that is, the beam diameter was

• transitions using the Tauc method. Structure and elemental composition Surface properties The oxidation state of copper on the surface of (Ti0.48Cu0.52)Ox thin film was analyzed with the XPS Cu 2p core level spectrum (Figure 6). The Cu 2p core level has split spin–orbit components with ΔBE of 19.8 eV and an

Relationship between corrosion and nanoscale friction on a metallic glass

• Haoran Ma and
• Roland Bennewitz

Beilstein J. Nanotechnol. 2022, 13, 236–244, doi:10.3762/bjnano.13.18

• outer layer after polarization [21], they did not show a clear distinction of the top of the outer layer after immersion. Maurice et al. [32] found that the thickness of the outer layers on stainless steel surfaces is similar during immersion and after polarization (0.5–0.7 nm) using XPS analysis

Impact of device design on the electronic and optoelectronic properties of integrated Ru-terpyridine complexes

• Max Mennicken,
• Sophia Katharina Peter,
• Corinna Kaulen,
• Ulrich Simon and
• Silvia Karthäuser

Beilstein J. Nanotechnol. 2022, 13, 219–229, doi:10.3762/bjnano.13.16

• -SAc)–AuNPs, with an average size of 12.9 ± 1.6 nm (Supporting Information File 1, Figure S2). Ru(TP)2-complex wire growth For the tracking of the Ru(TP)2-complex wire formation via XPS measurements mica substrates of 8 × 4 mm2 covered by a 200 nm Au(111) layer were used. In a first step the substrates

• . Instrumentation X-ray photoelectron spectroscopy (XPS) measurements were conducted with a PHI5000 VersaProbe II using monochromatic Al Kα radiation (1.486 keV). Survey scans (187.5 eV pass energy, 0.8 eV/step) and core level spectra (23.5 eV pass energy, 0.1 eV/step) of the elements C 1s, N 1s, O 1s, S 1s, Ru 3d

• were monitored by XPS measurements. The step-by-step formation of the Ru(TP)2-complex wires was conducted starting with the assembly of MPTP on Au substrates, corresponding to samples (i) (Figure 1). Then the substrates were incubated in a Ru-PF6 solution, leading to the formation of the Ru-MPTP half

Low-energy electron interaction and focused electron beam-induced deposition of molybdenum hexacarbonyl (Mo(CO)₆)

• Po-Yuan Shih,
• Maicol Cipriani,
• Christian Felix Hermanns,
• Jens Oster,
• Klaus Edinger,
• Armin Gölzhäuser and
• Oddur Ingólfsson

Beilstein J. Nanotechnol. 2022, 13, 182–191, doi:10.3762/bjnano.13.13

• rapidly with increased electron dose and was already insignificant above 1 × 1017 e−/cm2. An XPS analysis of the remaining deposit revealed an average loss of two CO groups from the W(CO)6 adsorbate at about 7 × 1016 e−/cm2, but above that dose the dominating pathway becomes electron-induced CO

Tin dioxide nanomaterial-based photocatalysts for nitrogen oxide oxidation: a review

• Viet Van Pham,
• Hong-Huy Tran,
• Thao Kim Truong and
• Thi Minh Cao

Beilstein J. Nanotechnol. 2022, 13, 96–113, doi:10.3762/bjnano.13.7

• reports still proposed its photocatalytic behaviors partly based on •O2− species via the combination of experimental physicochemical analyses, such as electron spin resonance (ESR) spectroscopy, active species trapping experiments, valence band X-ray photoelectron spectroscopy (XPS), and diffuse

• •O2− radicals played a primary role in the photocatalytic NO oxidation. Additionally, using photoluminescence (PL) spectroscopy, XPS, active species trapping tests, and ESR spectroscopy, the authors studied the photoinduced charge migration and trapping. They proposed the band structure of the SnO2

• photocatalytic oxidation ability of SnO2. Ultraviolet–visible absorption spectra (a) and corresponding bandgaps of SQDs (b). Figure 3 was reprinted from [46], Materials Letters, vol. 221, by Babu, B.; Neelakanta Reddy, I.; Yoo, K.; Kim, D.; Shim, J. “Bandgap tuning and XPS study of SnO2 quantum dots”, pages 211

Sputtering onto liquids: a critical review

• Anastasiya Sergievskaya,
• Adrien Chauvin and
• Stephanos Konstantinidis

Beilstein J. Nanotechnol. 2022, 13, 10–53, doi:10.3762/bjnano.13.2

Chemical vapor deposition of germanium-rich CrGe_x nanowires

• Vladislav Dřínek,
• Stanislav Tiagulskyi,
• Roman Yatskiv,
• Jan Grym,
• Radek Fajgar,
• Věra Jandová,
• Martin Koštejn and
• Jaroslav Kupčík

Beilstein J. Nanotechnol. 2021, 12, 1365–1371, doi:10.3762/bjnano.12.100

• multiplet peaks at higher binding energies associated with elemental Cr/germanide (CrGex) and multiplet splitting of the Cr(III) oxide species [13], respectively (Figure 4b). We were not able to separate elemental Cr and CrGex subpeaks as the XPS shift of a metal (chromium)/germanium in metal (chromium

• first part of the furnace. The Cr(acac)3 vapor in a continuous flow (3 sccm) of germane (GeH4) at 250 Pa was transported to the second part of the furnace where pyrolysis took place at 500 °C over molybdenum substrates. X-ray photoelectron spectrometry (XPS, Kratos ESCA 3400 with a base pressure below

Plasmon-enhanced photoluminescence from TiO₂ and TeO₂ thin films doped by Eu³⁺ for optoelectronic applications

• Marcin Łapiński,
• Jakub Czubek,
• Katarzyna Drozdowska,
• Anna Synak,
• Wojciech Sadowski and
• Barbara Kościelska

Beilstein J. Nanotechnol. 2021, 12, 1271–1278, doi:10.3762/bjnano.12.94

• investigated by SEM and TEM, while the composition of oxides film was analyzed by XPS. Luminescence properties were studied on the basis of excitation and emission spectra. The experiments show that the additional dielectric layer enhances the luminescence intensity. Such structures could be potential

• spectroscopy (XPS). Measurement was performed using Omicron Nanotechnology equipment at room temperature and under ultrahigh vacuum conditions, at a pressure below 1.1 × 10−6 Pa. A Mg Kα X-ray source was operated at 15 kV and 300 W. XPS analysis were performed using CASA XPS software package with Shirley

• decrease of transmittance at 350 nm is caused by absorption of glass substrate and can be noticed for other samples as well. TiO2:Eu-based structures The chemical composition of the luminescent titanium dioxide doped with europium was examined using XPS. The spectra of Ti 2p and Eu 4d core level electrons

The effect of cobalt on morphology, structure, and ORR activity of electrospun carbon fibre mats in aqueous alkaline environments

• Markus Gehring,
• Tobias Kutsch,
• Osmane Camara,
• Alexandre Merlen,
• Hermann Tempel,
• Hans Kungl and
• Rüdiger-A. Eichel

Beilstein J. Nanotechnol. 2021, 12, 1173–1186, doi:10.3762/bjnano.12.87

• electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDX), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), Raman spectroscopy, elemental analysis, and inductively coupled plasma optical emission spectrometry (ICP-OES). In addition, the fibres were analysed in terms of their

• , samples of 1 cm2 were cut from the fibre mats and fixed on a silicon crystal in a rotating sample holder. The scan range was limited to 10° to 80°, scanned with a step width of 0.01°. X-ray photoelectron spectroscopy (XPS) was performed with a Phi5000 VersaProbe II (ULVAC-Phi Inc., USA). Spectra were

• recorded with a resolution of 0.1 eV using Al Kα radiation (1.486 keV) at 50 W and a spot size of 200 μm. Fitting the cobalt XPS spectra follows the suggestions from Biesinger et al. [24] based on the complex multiplet structure of cobalt [25]. Based on these reports the Co 2p range was examined in detail

Irradiation-driven molecular dynamics simulation of the FEBID process for Pt(PF₃)₄

• Alexey Prosvetov,
• Alexey V. Verkhovtsev,
• Gennady Sushko and
• Andrey V. Solov’yov

Beilstein J. Nanotechnol. 2021, 12, 1151–1172, doi:10.3762/bjnano.12.86

• influence the rate of precursor molecule fragmentation. The chosen value of the deposited energy can be verified by comparing the dependence of surface coverage of precursor elements on the electron dose with the experimental data measured by means of X-ray photoelectron spectroscopy (XPS). Electron energy

Progress and innovation of nanostructured sulfur cathodes and metal-free anodes for room-temperature Na–S batteries

• Marina Tabuyo-Martínez,
• Bernd Wicklein and
• Pilar Aranda

Beilstein J. Nanotechnol. 2021, 12, 995–1020, doi:10.3762/bjnano.12.75

• , polysulfides are converted to polythionate [O3S2–(S)x−2–S2O3] complexes bound to the electrode surface, which inhibits the shuttle effect [12]. A similar electrochemical mechanism has been reported by Kumar et al. [51] based on XPS analyses. The results show that the interaction between MnO2 and long-chain

Impact of GaAs(100) surface preparation on EQE of AZO/Al₂O₃/p-GaAs photovoltaic structures

• Piotr Caban,
• Rafał Pietruszka,
• Jarosław Kaszewski,
• Monika Ożga,
• Bartłomiej S. Witkowski,
• Krzysztof Kopalko,
• Piotr Kuźmiuk,
• Katarzyna Gwóźdź,
• Ewa Płaczek-Popko,
• Krystyna Lawniczak-Jablonska and
• Marek Godlewski

Beilstein J. Nanotechnol. 2021, 12, 578–592, doi:10.3762/bjnano.12.48

• ) and scanning electron microscopy (SEM) examinations were conducted to obtain structural details of the devices. X-ray photoelectron spectroscopy (XPS) with depth profiling was used to examine interface structure and changes in the elemental content and chemical bonds. The photoluminescence (PL

• characteristics were collected under standard test conditions (STC) using a PET solar simulator, model #SS100AAA. UV–vis absorbance and reflectance measurements were conducted with the use of a Varian Cary 5000 spectrophotometer equipped with a DRA 2500 integrating sphere accessory. The XPS measurements were

• 2p and Zn, Ga and As 3d spin–orbit doublets were measured. The spectra were analyzed using the commercial CASA XPS software package (Casa Software Ltd, version 2.3.17) with Shirley background. The spectra were fitted with a mixed Gaussian–Lorentzian (GL(30)) function. The depth profiling was

The preparation temperature influences the physicochemical nature and activity of nanoceria

• Robert A. Yokel,
• Wendel Wohlleben,
• Johannes Georg Keller,
• Matthew L. Hancock,
• Jason M. Unrine,
• D. Allan Butterfield and
• Eric A. Grulke

Beilstein J. Nanotechnol. 2021, 12, 525–540, doi:10.3762/bjnano.12.43

• reported to be uncoated [24]. However, it was found that its surface had organic contaminations, shown by thermogravimetric analysis (<0.7 % of the material [7]). Further investigation with XPS, which has an information depth between 3 and 10 nm, indicated 80% carbon atoms on the surface. Photoelectron

Interface interaction of transition metal phthalocyanines with strontium titanate (100)

• Reimer Karstens,
• Thomas Chassé and
• Heiko Peisert

Beilstein J. Nanotechnol. 2021, 12, 485–496, doi:10.3762/bjnano.12.39

• resublimed before usage. The materials were evaporated from temperature-controlled crucibles. The nominal layer thickness was estimated from substrate- and adsorbate-related XPS intensity ratios using photoemission cross sections from Yeh and Lindau [41]. A nominal monolayer of lying molecules corresponds to

• –F bond dissociation. However, uncertainties in the estimation of the monolayer thickness from XPS intensities only cannot be ruled out completely. FePcFx on STO(100) To investigate whether the observed local interaction between the central metal atom of CoPcFx (x = 0 or 16) and the STO substrate is

Boosting of photocatalytic hydrogen evolution via chlorine doping of polymeric carbon nitride

• Malgorzata Aleksandrzak,
• Michalina Kijaczko,
• Wojciech Kukulka,
• Daria Baranowska,
• Martyna Baca,
• Beata Zielinska and
• Ewa Mijowska

Beilstein J. Nanotechnol. 2021, 12, 473–484, doi:10.3762/bjnano.12.38

• Cl modification resulted in the maintenance of the chemical skeleton [43][44][45][46][47]. The chemical composition and relative atomic percentages of the obtained materials were analyzed by X-ray photoelectron spectroscopy (XPS). The XPS spectra revealed that the samples are composed of carbon

• -chloro-4,6-diamino-1,3,5-triazine (CDATA) increased the amount of carbon whereas it decreased the amount of nitrogen. Simultaneously, a slight increase in the atomic concentration of oxygen was observed. The XPS spectra revealed 0.18 atom % of chlorine in Cl-PCN. The detailed analysis of the chemical

• other hand, the amount of C–C/C=C/N3C significantly decreases. The XPS analysis indicates a successful incorporation of chlorine into the polymeric carbon nitride network. Without the doping agent melamine, thermal polycondensation leads to the formation of melon. We suppose that the presented synthesis

Structural and optical characteristics determined by the sputtering deposition conditions of oxide thin films

• Petronela Prepelita,
• Florin Garoi and
• Valentin Craciun

Beilstein J. Nanotechnol. 2021, 12, 354–365, doi:10.3762/bjnano.12.29

• diffraction (XRD) and X-ray photoelectron spectroscopy (XPS), while the surface topography of the samples was analyzed using scanning electron microscopy (SEM). The optical characteristics were measured for samples with the same composition but obtained with different deposition parameters, such as increasing

• thickness of the deposited SiO2 and ZnO thin films, several methods were applied, including XPS, XRD, and SEM. Hence, the ESCALAB 250+ XPS equipment was used to determine the surface composition of the samples with the following specifications: monochromatic Al Kα radiation (1486.6 eV) and vacuum in the

• thermal treatment, which induces an internal stress in the ZnO thin films. To the same extent, with the depositions made at room temperature on all SiO2 thin films, their structure proved to be essentially amorphous [28][37] with no sharp XRD reflection lines and featuring a matte surface. Based on XPS

Nickel nanoparticle-decorated reduced graphene oxide/WO₃ nanocomposite – a promising candidate for gas sensing

• Ilka Simon,
• Alexandr Savitsky,
• Rolf Mülhaupt,
• Vladimir Pankov and
• Christoph Janiak

Beilstein J. Nanotechnol. 2021, 12, 343–353, doi:10.3762/bjnano.12.28

• using XPS and Raman spectroscopy. Such bonds can play an important role also in our case with regard to charge transfer. It has been established that adsorption of NO2 molecules will cause upward band bending by capturing free electrons from the conduction band and shift the Fermi level of WO3 away from

Scanning transmission helium ion microscopy on carbon nanomembranes

• Daniel Emmrich,
• Annalena Wolff,
• Nikolaus Meyerbröker,
• Jörg K. N. Lindner,
• André Beyer and
• Armin Gölzhäuser

Beilstein J. Nanotechnol. 2021, 12, 222–231, doi:10.3762/bjnano.12.18

• between the two cases, and the error of this particular measurement is 9%. To test the validity of the determined thickness and the approach described above, the results from the STIM dark-field imaging are compared to X-ray photoelectron spectroscopy (XPS) and energy-filtered transmission electron

• microscopy (EFTEM) data, both being established techniques for the thickness measurement of thin films. All three presented methods, STIM, XPS, and EFTEM, require an assumption about density and composition of the material in order to calculate absolute thicknesses, so graphite was chosen as a well

• -characterized material. XPS collects the signal from a measurement spot with a diameter of a few hundred micrometers. It has, therefore, a much lower lateral resolution than STIM. It requires the membrane to be placed on a solid bulk material. Therefore, from the same membrane batch used for STIM measurements

Fusion of purple membranes triggered by immobilization on carbon nanomembranes

• René Riedel,
• Natalie Frese,
• Fang Yang,
• Martin Wortmann,
• Raphael Dalpke,
• Daniel Rhinow,
• Norbert Hampp and
• Armin Gölzhäuser

Beilstein J. Nanotechnol. 2021, 12, 93–101, doi:10.3762/bjnano.12.8

• histidine-tag at the extracellular side of a PM mutant (c-His PM). The functionalization and the resulting hybrid membrane were examined by atomic force microscopy (AFM), scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), confocal laser scanning microscopy (CLSM), and infrared

• . Afterwards the sample was rinsed with ethanol, dried in a stream of nitrogen, and stored under argon gas. Sample characterization X-ray photoelectron spectroscopy (XPS) has been conducted in an Omicron Multiprobe UHV system (Scienta Omicron GmbH, Taunusstein, Germany) using monochromatic Al Kα irradiation, a

• are reversible. Furthermore, the functionalization was investigated utilizing XPS and IRRAS as seen in Figure 2c,d. The IRRAS spectrum of an NBPT CNM after the first functionalization step reveals a peak at 2106 cm−1 caused by the asymmetrical stretching vibration of the azide moiety, which indicates

Free and partially encapsulated manganese ferrite nanoparticles in multiwall carbon nanotubes

• Saja Al-Khabouri,
• Salim Al-Harthi,
• Toru Maekawa,
• Mohamed E. Elzain,
• Ashraf Al-Hinai,
• Ahmed D. Al-Rawas,
• Abbsher M. Gismelseed,
• Ali A. Yousif and
• Myo Tay Zar Myint

Beilstein J. Nanotechnol. 2020, 11, 1891–1904, doi:10.3762/bjnano.11.170

• ) overnight. X-ray photoelectron spectroscopy (XPS, Omicron Nanotechnology) was employed with a monochromatic Al Kα radiation (hν = 1486.6 eV), with a source voltage of 15 kV and an emission current of 20 mA. Scans were carried out at a base pressure of 2 × 10−8 Pa. A wide scan was recorded at a constant

• analyzer transmission energy of 50 eV, while the individual elemental peaks were recorded at an analyzer pass energy of 20 eV. All XPS measurements were carried out at room temperature and no heating was performed prior to the XPS measurement. The obtained XPS spectra were deconvoluted using the CasaXPS

• Fe2+ is undetectable, as shown in Table 1. These results indicate that the divalent cations in free MnFe2O4 nanoparticles are Mn2+, which supports the XPS data in Figure 2. The Mössbauer spectrum in Figure 1f shows sextets, which are attributed to the field arising from larger particles superimposed

Unravelling the interfacial interaction in mesoporous SiO₂@nickel phyllosilicate/TiO₂ core–shell nanostructures for photocatalytic activity

• Bridget K. Mutuma,
• Xiluva Mathebula,
• Isaac Nongwe,
• Bonakele P. Mtolo,
• Boitumelo J. Matsoso,
• Rudolph Erasmus,
• Zikhona Tetana and
• Neil J. Coville

Beilstein J. Nanotechnol. 2020, 11, 1834–1846, doi:10.3762/bjnano.11.165

• @NiPS/TiO2) core–shell nanostructures. The TEM results showed that the mSiO2@NiPS composite has a core–shell nanostructure with a unique flake-like shell morphology. XPS analysis revealed the successful formation of 1:1 nickel phyllosilicate on the SiO2 surface. The addition of TiO2 to the mSiO2@NiPS

• , and X-ray photoelectron spectroscopy (XPS) were used to elucidate the morphological and textural features, optoelectronic properties, and elemental composition of the core–shell nanomaterials. These core–shell nanostructures were also employed as catalysts in a model reaction, that is, the

• hydroxy groups bonded to nickel atoms (δ(NiO–H) band) in NiPS as multiple peaks were recorded between 630 and 710 cm−1 [57]. XPS analysis of mSiO2@NiPS and mSiO2@NiPS/TiO2 X-ray photoelectron spectroscopy (XPS) was used to study the surface composition of mSiO2@NiPS and mSiO2@NiPS/TiO2. The complete scans

Self-standing heterostructured NiC_x-NiFe-NC/biochar as a highly efficient cathode for lithium–oxygen batteries

• Shengyu Jing,
• Xu Gong,
• Shan Ji,
• Linhui Jia,
• Bruno G. Pollet,
• Sheng Yan and
• Huagen Liang

Beilstein J. Nanotechnol. 2020, 11, 1809–1821, doi:10.3762/bjnano.11.163

• energy-dispersive X-ray spectroscopy (EDX) were carried out on a FEI Tecnia G2 F20 high-resolution transmission electron microscope operating at 200 kV. The surface composition of the samples was analyzed by X-ray photoelectron spectroscopy (XPS) on a ESCALAB 250Xi electron energy spectrometer using Al

• surface of NiFe-PBA/PP-T samples, NiFe-PBA/PP-T was investigated via XPS (Figure 4). In the C 1s XPS spectra of NiFe-PBA/PP-T (Figure 4a), the binding energy values of 284.8, 285.3, 286.2, and 289 eV correspond to C–C, C=C, C–N, and C–O species, respectively [29][47][48]. For NiFe-PBA/PP-900, the peak at

• 283.2 eV corresponds to metal–carbon bonds, which indicates the formation of transition metal carbides at a higher calcination temperature. As shown in Figure 4b, the N 1s XPS spectrum consists of three main peaks at 398.5, 399.8 and 400.8 eV, corresponding to pyridinic nitrogen, metal–nitrogen, and

Electron beam-induced deposition of platinum from Pt(CO)₂Cl₂ and Pt(CO)₂Br₂

• Aya Mahgoub,
• Hang Lu,
• Rachel M. Thorman,
• Konstantin Preradovic,
• Titel Jurca,
• Lisa McElwee-White,
• Howard Fairbrother and
• Cornelis W. Hagen

Beilstein J. Nanotechnol. 2020, 11, 1789–1800, doi:10.3762/bjnano.11.161

• for complete precursor decomposition [14]. Electron-induced decomposition of adsorbed Pt(CO)2Cl2 has been previously studied using X-ray photoelectron spectroscopy (XPS) and mass spectrometry, and some deposits were produced in the ultrahigh vacuum (UHV) environment of an Auger electron spectroscopy

PEG/PEI-functionalized single-walled carbon nanotubes as delivery carriers for doxorubicin: synthesis, characterization, and in vitro evaluation

• Shuoye Yang,
• Zhenwei Wang,
• Yahong Ping,
• Yuying Miao,
• Yongmei Xiao,
• Lingbo Qu,
• Lu Zhang,
• Yuansen Hu and
• Jinshui Wang

Beilstein J. Nanotechnol. 2020, 11, 1728–1741, doi:10.3762/bjnano.11.155

• 3000HS). A volume-weighted Gaussian size distribution was fit to the autocorrelation functions to obtain the particle size and zeta potential values. The atomic fractions of C, O, and N in the different SWCNTs samples were determined by X-ray photoelectron spectroscopy (XPS, Thermo Fisher Scientific

• PEI. Considering the results, SWCNTs were purified and shortened with H2SO4/HNO3 in the subsequent experiments. The XPS spectra of different nanocarriers are shown in Figure 4A and Figure 4B. A C 1s peak with a binding energy of 285 eV appears for raw SWCNTs. In the CNTs-COOH samples a peak at 532.5

• different acid solutions: (B) H2SO4/H2O2, (C) HNO3, (D) H2SO4/HNO3, (E) CNTs-PEG and (F) CNTs-PEG-PEI. Characterization of different nanocarriers. (A, B) XPS spectra, (C) FTIR spectra, (D) XRD diffraction patterns (a: raw SWCNTs; b–d: CNTs-COOH synthesized using different acid solutions, b: H2SO4/H2O2, c

Cu₂O nanoparticles for the degradation of methyl parathion

• Juan Rizo,
• David Díaz,
• Benito Reyes-Trejo and
• M. Josefina Arellano-Jiménez

Beilstein J. Nanotechnol. 2020, 11, 1546–1555, doi:10.3762/bjnano.11.137

• through UV–vis absorption of 4-NPh. Likewise, it was shown that the surface basicity increases with decreasing nanoparticle size. The presence of CuCO3 on the surface of Cu2O, identified using X-ray photoelectron spectroscopy (XPS), passivates its surface and consequently diminishes the degradation of MP

• width of 45°, acquisition time of 0.813 s, FT size of 65 K and digital resolution of 0.5 Hz per point. The number of scans varied from 512 to 4,096 per spectrum. X-ray photoelectron spectroscopy (XPS) were measured in a ESCA/SAM Perkin-Elmer model 560, using an Al Kα source with a 400 μm spot diameter

• (bright red powder). The colored powders can be seen in Figure 2, as well as their color in aqueous dispersion. It is important to mention that there is no evidence in XRD for the presence of CuO or CuCO3, although these compouds are observed in XPS. Figure 3a shows the HRTEM image of a typical Cu2O