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Crosslinked hydrogel brushes were grafted from stainless steel (SS) surfaces for marine antifouling. The brushes were prepared by surface-initiated atom transfer radical polymerization (SI-ATRP) of 2-methacryloyloxyethyl phosphorylcholine (MPC) and poly(ethylene glycol) methyl ether methacrylate (PEGMA) respectively with different fractions of crosslinker in the feed. The grafted layers prepared with different thickness were characterized by X-ray photoelectron spectroscopy (XPS), atomic force microscopy (AFM), ellipsometry and water contact angle measurements. With the increase in the fraction of crosslinker in the feed, the thickness of the grafted layer increased and the surface became smooth. All the brush-coated SS surfaces could effectively reduce the adhesion of bacteria and microalgae and settlement of barnacle cyprids, as compared to the pristine SS surface. The antifouling efficacy of the PEGMA polymer (PPEGMA)-grafted surface was higher than that of the MPC polymer (PMPC)-grafted surfaces. Furthermore, the crosslinked hydrogel brush-grafted surfaces exhibited better fouling resistance than the non-crosslinked polymer brush-grafted surfaces, and the antifouling efficacy increased with the crosslinking density. These hydrogel coatings of low toxicity and excellent anti-adhesive characteristics suggested their useful applications as environmentally friendly antifouling coatings. [ABSTRACT FROM AUTHOR]

[Display omitted] • A fast reduction of U6+ to U4+ occurs on semiconductors during XPS measurement. • Slower breakage of uranyl occurs on non-semiconductors under X-ray irradiation. • XPS measurement could change the elements state even if far from the center of beam. • Measures are proposed to reduce the beam induced effects in XPS measurement. X-ray photoelectron spectroscopy (XPS) is an efficient technique for recognizing the state of elements. However, the effects of X-ray irradiation on change in the chemical state are sometimes ignored, which may impair the understanding of the environmental behavior of these elements. This study determined the change in the U 4f spectra induced by X-ray irradiation during XPS detection. For U(VI) on non-semiconductors, X-ray irradiation led to a negative shift of U 4f 7/2 to ∼ 380.8 eV due to the break of the uranyl molecules, but not resulting in U(IV) species. However, owing to the photocatalytic reduction of U(VI), the irradiation of U(VI) loaded semiconductors rapidly induced the negative shift of U 4f 7/2 peak to ∼ 379.8 eV, which is the characteristic of U(IV). Moreover, apparent photo-reduction occurred even if the samples were far from the center of the X-ray beam (>3971 μm). Based on these findings, methods for reducing potential error due to X-ray irradiation are suggested, including using the minimum scan time, measuring uranium-containing samples first or independent of other samples, and using X-ray of lower intensity. The results indicated that X-ray induced alteration to the chemical states must be considered when using X-ray techniques. [ABSTRACT FROM AUTHOR]

Abstract: A novel and simple method for preparing F-doped anatase TiO2 (defined as FTO) film with high photocatalytic activity was developed using titanium-n-butoxide and NH4F as TiO2 and fluorine precursors under mild condition, i.e. low temperature (lower than 373K) and ambient pressure. The prepared samples were characterized by XRD, SEM, X-ray photoelectron spectroscopy (XPS), diffuse reflectance spectrum (DRS), photoluminescence spectrum (PL) and TG–DSC analysis. The photocatalytic activity was evaluated by decomposing X-3B under artificial solar light. The results showed that the crystallinity of TiO2 was improved by F-doping. F− ions can prevent the grain growth, and the transformation of anatase to rutile phase was also inhibited. The doped fluorine atoms existed in two chemical forms, and the ones incorporated into TiO2 lattice might take a positive role in photocatalysis. Compared with surface fluorination samples, FTO film exhibited better photocatalytic activity. The high photocatalytic activity of FTO may due to extrinsic absorption through the creation of oxygen vacancies rather than the excitation of the intrinsic absorption band of bulk TiO2. Furthermore, the FTO can be recycled with little photocatalytic activity depression. Without any further treatment besides rinsing, after 6 recycle utilization, the photocatalytic activity of FTO film was still higher than 79%. [Copyright &y& Elsevier]

• Trace metal Ni0 successfully attached to HNTs by electroless plating. • The catalyst reduced the reaction temperature to 400 °C with 99% removal rate. • The nickel ferrite exhibited excellent anti-toxic performance. • PH 3 dissociation on Ni was calculated by a first-principle calculation using DFT. • The P layer formed on Ni0 surface was critical to PH 3 successive decomposition. Nickel ferrite (NiFe 2 O 4) nanocatalysts with trace metal nickel (Ni0) as the reaction trigger were dispersedly supported by halloysite nanotubes (HNTs) to decompose toxic phosphine (PH 3) into yellow phosphorus and hydrogen. The mixed spinel catalyst greatly reduced the temperature to 400 °C for 99% conversion and underwent no obvious deactivation after 2 h compared with magnetite. The as-synthesized and spent catalysts were characterized by Transmission electron microscope, X-ray powder diffraction and X-ray photoelectron spectroscopy. In combination with density functional theory calculations, the PH 3 decomposition mechanism on Ni0@NiFe 2 O 4 /HNTs was proposed. The original plated Ni0 triggers the reaction to form active H radicals ([▾H]) contributing to the reduction of octahedral Ni(II) in NiFe 2 O 4 , and the newly generated Ni0 determines the catalytic activity and stability. In addition, the formation of Ni 2 P is crucial to developing the stable elemental phosphorus (P) layer as the mainly active intermediate for PH 3 successive decomposition into P 4 , since P layer reduces the activation barrier of PH 3 decomposition. Particularly, the mixed crystal spinel with specific coordination (with octahedral coordinated Fe(II) and tetrahedral coordinated defects) facilitates the electron transfer among the active species to recycle the catalytic reaction. This work provides a promising approach for PH 3 air-pollution control and P recovery from the industrial off-gas. [ABSTRACT FROM AUTHOR]

[Display omitted] • Proanthocyanidin (PAC) and chitosan encapsulated proanthocyanidin (CS-PAC) can be covalently immobilized to titanium surface through silane coupling strategy. • Silane coupling coatings exhibit better wear and compression resistances than physically adsorbed coatings. • Both strong chemical bonding and nanoparticles that act as roller-bearings contribute to the superior mechanical properties. • Silane coupling strategy will not influence the cell-adhesion-, proliferation-, and differentiation-promoting properties as well as antioxidant properties of PAC and CS-PAC. Typical strategies used to improve the osteo-inductive and antioxidative capacities of titanium and its alloys involve loading with functional molecules, such as proanthocyanidin (PAC), by physical adsorption, which limits the bonding strength and durability of the coating. Accordingly, in the present study, (3-aminopropyl) triethoxysilane (APTES) and glutaraldehyde (GA) were used to prepare covalently immobilized PAC and chitosan-encapsulated PAC (CS-PAC) coatings on Ti surface. Quantum chemistry and X-ray photoelectron spectroscopy analyses confirmed the chemical grafting of PAC and CS-PAC onto the Ti surfaces. Their superior wear and compression resistances were demonstrated by friction and nanoindentation testing. SEM observation of the surface revealed that the improvement of mechanical properties is not only related to the formation of chemical bonds, but also to the presence of nanoparticles that act as roller bearings. Contact angle measurement and TEM observation were also used for surface analysis. The murine pre-osteoblast cell line MC3T3-E1 was used to assess the osteo-inductive and antioxidative activities of the coatings under H 2 O 2 -induced oxidative stress in vitro. The cell-adhesion-, proliferation-, and differentiation-promoting properties as well as antioxidant properties of PAC are retained after the formation of chemical bonds to APTES. Thus, this silane coupling strategy can enhance the mechanical properties of PAC nanocoatings while preserving their biological activity. [ABSTRACT FROM AUTHOR]

Oxygen vacancies enriched CuO nanoflakes was reported to accelerate the adsorbed hydroxyl ions to promote the formation of Cu3+ species, which reduce the one-potential and facilitate the glucose oxidation. [Display omitted] • CuO nanoflakes with abundant surface oxygen vacancies was simply synthesized. • High-angle annular dark-field image, X-ray photoelectron spectroscopy, and electron spin resonance were employed to prove the existence of enriched oxygen vacancies. • Oxygen vacancies improve the adsorption and stabilization of OH– to in favor of the formation of Cu3+ species, which reduces the onset-potential and facilitates the glucose oxidation. • lower onset-potential of +0.22 V, ultrahigh sensitivity of 4870 μA mM−1 cm−2, higher selectivity, fast response time with about 2s were obtained as glucose sensor. The construction of oxygen vacancies, as one of defects engineering, is a promising strategy to boost the electrocatalytic activity. Herein, CuO nanoflakes enriched with oxygen vacancies were successfully synthesised via a simple one-pot method with stirring. High-angle annular dark-field scanning, X-ray photoelectron spectroscopy and electron spin resonance spectroscopy were performed to confirm the existence of enriched oxygen vacancies. The as-synthesised CuO nanoflakes enriched with oxygen vacancies and exhibited an excellent performance for glucose detection with a lower onset-potential of +0.22 V, ultrahigh sensitivity of 4870 μA mM−1 cm−2 and low detection limit of 0.5 μM. The superior performance of the CuO nanoflakes may be attributed to surface oxygen vacancies, which accelerate the adsorbed hydroxyl ions to promote the formation of Cu3+ species, thereby, reducing the one-potential and facilitating the glucose oxidation. This work would serve the guide for the rational design of other efficient catalysts for glucose detection via constructing oxygen vacancies. [ABSTRACT FROM AUTHOR]

[Display omitted] • In3+ ions were introduced in ITO films to regulate defects using SCCO 2 fluid. • The photoelectric properties of ITO films were improved after SCCO 2 fluid treatment. • The mechanism for the enhanced performance of ITO films is proposed. The carrier concentration of the indium tin oxide (ITO) thin films can be enhanced by supplying extra conducting electrons with tin dopants. However, defects and impurities, which are rich around grain boundaries, result in strong carrier scattering. In this work, ITO films prepared by magnetron sputtering were subjected to supercritical carbon dioxide (SCCO 2) fluid treatment with different concentrations of InCl 3 solutions, In3+ ions were introduced in the grain boundaries for the purpose of regulating defects and impurities there. The photoelectric performance of ITO films was improved significantly after the SCCO 2 fluid treatments, which was interpreted for the effects of SCCO 2 on as-deposited ITO microstructures based on the experimental results of X-ray photoelectron spectroscopy and positron annihilation lifetime spectroscopy. Upon the SCCO 2 fluid treatment, the dehydration effect passivated the dangling bonds around the grain boundaries, meanwhile, the indium ions diffused into the grain boundaries, resulting in the formation of ITO-like lattice structure there. [ABSTRACT FROM AUTHOR]

• The Ni1Co3@BC hybrid were prepared with ultrasonic stripping and pyrolysis methods. • The B-doped graphitization structure plays additional active sites for OER activity. • Ni1Co3@BC hybrid exhibits the excellent durability, due to internal active sites were protected coming from the carbon layers. Designing and construction of efficient and robust non-noble-metal electrocatalysts for oxygen evolution reaction (OER) is a pivotal approach in water splitting process. This work developed the dual-metal material system of Ni-Co nanoparticles wrapped in B-doped carbon (Ni1Co3@BC) through simple and economical pyrolysis process for nanosheets NiCo metal-organic framework (Ni1Co3-BDC) precursor. The constitution and structure of characterization were characterized by X-ray diffraction, X-ray photoelectron spectroscopy scanning electron microscope and transmission electron microscope, indicating the homogeneous alloy and less metal boride phase and B doped graphitization structure for Ni1Co3@BC. An optimized Ni1Co3@BC exhibited extraordinary OER performance, providing an overpotential as small as 309 mV at a current density of 10 mA cm−2, a low Tafel slope of 62 mV dec−1 and excellent stability in 1.0 M KOH solution, which attributed to the synergistic effect of inner NiCo alloy, NiCo boride nanoparticles and external B doping carbon structure. The formation of B doped carbon layer not only provides additional active sites but also protects inner metal alloys. This work clearly stated the design and synthesis of desired-morphology features catalysts from controlled MOFs for energy conversation and storage. [ABSTRACT FROM AUTHOR]

• Superhydrophobic and antibacterial fabric was achieved by in situ growing ZIF-8 and PDMS coating. • Fabricated fabric demonstrated high oil/water separation capacity. • As-prepared fabric showed excellent antibacterial activity against E. coli and S. aureus. • Samples exhibited excellent good abrasion resistance and laundering stability. Facile construction of multifunctional fabrics with durability still remains a challenge in the past decade. In this work, we report a facile fabrication of non-fluorinated superhydrophobic and antibacterial cotton fabric surfaces via in situ growing zeolitic imidazolate framework-8 (ZIF-8) nanocrystals on cotton fibers under room temperature condition and subsequently coating with polydimethylsiloxane (PDMS). The surface morphology and chemical composition of treated fabric have been characterized by scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDS), X-ray diffraction analysis (XRD) and X-ray photoelectron spectroscopy (XPS). The as-prepared cotton fabric showed superhydrophobic property with a water contact angle (WCA) of 151.36° and a sliding angle of 3.6° and excellent antibacterial properties against E. coli and S. aureus. The durability of the superhydrophobic and antibacterial fabrics was evaluated by repeated washing and abrasion cycles. The as-prepared fabrics retained their excellent antibacterial property and superhydrophobicity after 300 cycles of abrasion and 5 cycles of washing. The robustness of superhydrophobicity and antibacterial activity made this method has wild application prospects in biomedical field in the future. [ABSTRACT FROM AUTHOR]

• Diatomite-supported birnessite–type MnO 2 were synthesized by two methods. • Mnx/DM-AO showed excellent performance for HCHO removal than Mnx/DM-MT. • The crystal defective, surface –OH and lattice oxygen were responsible for the reactivity. • The synergistic effect between diatomite and MnO 2 improved catalytic performance. Diatomite-supported birnessite–type MnO 2 (δ-MnO 2) with different loadings were synthesized through in-situ reduction method by methanol (Mnx/DM-MT) and hydrothermal reduction method by ammonium oxalate (Mnx/DM-AO), respectively. The as-synthesized catalysts were characterized by N 2 adsorption-desorption, X-Ray diffraction, transmission electron microscope, scanning electron microscope, Raman, H 2 -temperature programmed reduction, thermogravimetric, X-ray photoelectron spectroscopy, and in-situ diffuse reflectance infrared Fourier transform spectrometry, and then utilized to catalytic oxidation of formaldehyde at ambient temperature and low temperature (50–250 °C). Compared with the Mnx/DM-MT catalyst, the Mnx/DM-AO catalyst exhibited superior catalytic activity in degrading HCHO at ambient temperature and low temperature. The highly defective structure, abundant hydroxyl groups, rich lattice oxygen and Mn3+ species were responsible for the excellent performance of Mnx/DM-AO. Meanwhile, the Mnx/DM-AO still exhibited good stability obtained from the cyclic testing. In-situ DRIFTS analysis indicated that δ-MnO 2 provided the reactive site, while the diatomite carrier dispersed MnO 2 and also provides a small number of active sites. The synergistic effect between diatomite and δ-MnO 2 benefits the catalytic performance in removal HCHO. The advantages of high activity, low-cost and environment-friendly, suggested that Mn/DM-AO catalyst exhibits promising application foreground in catalytic oxidation of formaldehyde at the temperature from ambient to 250 °C. [ABSTRACT FROM AUTHOR]