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Perovskite oxide SrTiO 3 is a promising semiconductor photocatalyst for CO 2 reduction, which has two possible chemical surfaces—TiO 2 -terminated and SrO-terminated surfaces. Up to now, the effect of chemical surface and its modification on CO 2 adsorption, activation and sequential photocatalytic reduction is not established. In the work, SrTiO 3 , surface-Ti-rich SrTiO 3 and Sr(OH) 2 -decorated SrTiO 3 were prepared and their structural, surface, and optical properties and photocatalytic activity were explored. It is found that the absorption edge of surface-Ti-rich SrTiO 3 shifted toward visible-light region as compared with that of the other two photocatalysts, which is attributed to the decreased Ti 3d ground-state level at the surface. Bicarbonate- (HCO 3 − ) and bidentate carbonate-like (b-CO 3 = ) species are the main species for CO 2 adsorption on the surface-Ti-rich SrTiO 3 , whereas, besides HCO 3 − and b-CO 3 = , plenty of monodentate carbonate-like species (m-CO 3 = ) that has relatively low reactivity is present on the SrTiO 3 and Sr(OH) 2 -decorated photocatalysts. As a result, the surface-Ti-rich SrTiO 3 exhibits the highest activity for CO 2 reduction. Furthermore, although Sr(OH) 2 -decoration and SrO-terminated surfaces facilitate CO 2 fixing, the produced surface species are attached to the weakly active Sr ions, giving rise to the lower reactivity. The present work might supply a guide for designing highly active perovskite–type semiconductors for photocatalysis. [ABSTRACT FROM AUTHOR]

α-Fe 2 O 3 /BiOCl heterojunctions were synthesized by growing and assembling α-Fe 2 O 3 nanoplates to BiOCl microflowers via a two-step route to enhance the photocatalytic performance of BiOCl. The morphology, microstructure, element composition and optical properties of α-Fe 2 O 3 /BiOCl heterojunctions have been investigated by SEM, TEM, XRD, FT-IR, Raman spectra, XPS, UV–vis diffuse reflectance and PL spectra. Electrostatic interaction was a key to form α-Fe 2 O 3 /BiOCl heterojunctions. Compared with pure BiOCl, the synthesized α-Fe 2 O 3 /BiOCl heterojunctions possess an efficient visible light absorption and exhibit an improved of photocatalytic efficiency. A photocatalytic degradation mechanism has been proposed to explain that the heterojunctions enhance the separation efficiency of electron-hole pairs, and the holes are the main reactive species in the degratation of Rhodamine B. [ABSTRACT FROM AUTHOR]

The thrombus formation and oxidation of blood components caused by blood-contacting biomaterials were main reasons for poor hemocompatibility of biomaterials. To construct the anti-thrombotic and anti-oxidative surface, we electrospun styrene-b-(ethylene-co-butylene)-b-styrene elastomer (SEBS)/acylated Pluronic F127 (A-F127)/L-ascorbic acid (AA) microfibers based on the SEBS substrate in one step. Our strategy was based on that the phase-separation between SEBS and A-F127 during electrospinning resulted in hydrophilic surface of microfibers, the crosslinking of electrospun meshes rendered the surface stable, and the AA release from the microfibers interacted with blood cells actively to prevent blood cells from oxidative damage. We demonstrated that the self-assembly of SEBS/A-F127 blends resulted in the similar structure as core-shell microfibers with the A-F127 richness in the sheath; the presence of A-F127 on the out layer made the microfibers hydrophilic and rendered the microfibers anti-thrombotic; the release of AA from the microfibers in the PBS solution was temperature-dependent; AA acted as the antioxidant to decrease the oxidative damage of blood cells after long-term contact between biomaterials and blood. Our work paves a new way to develop long-term hemocompatible biomaterials, which may be helpful to prevent blood cells from oxidative damage to maintain the normal function of blood cells in vivo . [ABSTRACT FROM AUTHOR]

A mild and low-cost strategy for fabricating nanoporous silver (NPS) thin films loaded on Ni wire were reported via co-electrodeposition of Ag-Sn alloy and subsequent dealloying in alkaline solution. Scanning electron microscope (SEM) and energy dispersive spectrum (EDS) were performed to investigate the morphology and composition of the electrodes. The crystal structures of the precursor alloy and NPS were examined by X-ray diffraction (XRD). After selectively etching the Sn out of the Ag-Sn alloy, an unordered three-dimensional bicontinuous nanoporous structure was observed, with a pore size of ∼50–120 nm and a ligament size of ∼40–200 nm. The NPS electrodes presented linear current response to hydrogen peroxide under the concentration ranging from 0.010 to 8.000 mM, with an excellent correlation coefficient (R 2 ) of 0.99998. The high sensitivity, reliability, anti-interference ability, stability and short response time indicate its potential in real-time monitoring H 2 O 2 . [ABSTRACT FROM AUTHOR]

For CNT/N-Co@TiO 2 nanohybrids, integrated with 0D embedded Co and coated TiO 2 nanoparticles, 1D CNTs, 2D carbon nanolayers, 3D spherical networks, and doped N and Co heteroatoms, the multifunction synergism of improved adsorption, effective expansion buffering, excellent conductivity and efficient catalysis can enhance significantly rate capacity and cycle performance. [Display omitted] • CNT/N-Co@TiO 2 nanohybrid integrated with multi-dimension nanostructures is synthesized. • 3D CNT/N provide huge space for PS accommodation and high channel for electron and Li+ ion transfer. • 0D polar TiO 2 nanoparticles provide affluent bonding sites, enhancing the adsorption ability to PS. • 0D Co and TiO 2 nanoparticles provide electrocatalytic centers, enhancing reutilization of PS. • Synergism of adsorption, expansion, conductivity and catalysis enhance Li-S battery performance. Lithium-sulfur (Li-S) battery is considered as one of the most prospective energy storage devices; nevertheless, its application is seriously impeded owing to lithium polysulfide (LPS) shuttle, volume expansion, poor conductivity of sulfur, and weak redox kinetics between various LPSs. Herein, multiple-structure nanohybrids (CNT/N-Co@TiO 2), integrated with zero-dimensional (0D) embedded-Co and coated-TiO 2 nanoparticles, 1D carbon nanotubes, quasi-2D carbon nanolayer, 3D spherical networks, and N, Co-codoped heteroatoms, are synthesized. The multifunction synergism of improved adsorption, effective expansion buffering, excellent conductivity and efficient catalysis observably strengthens battery performance with CNT/N-Co@TiO 2 -modified separator. An initial discharge capacity of 1320 mAh g−1 can achieve at 0.2C, and meanwhile an initial discharge capacity of 1051 mAh g−1 can acquire with 0.071% capacity decay rate per cycle over 500 cycles at 1C. An initial specific discharge capacity of 653 mAh g−1 can show at 3C. Impressively, even at 5.1 mg cm−1 high sulfur loading, a distinguished cycling stability of 640 mAh g−1 can maintain after 60 cycles at 0.1C. This work demonstrates that high efficiency Li-S batteries can be implemented via a multifunction synergism of multiple-structure nanohybrids integrated with high conductivity carbon, polar metal oxide, and high catalytic activity embedded and coated nanoparticles and doped heteroatoms. [ABSTRACT FROM AUTHOR]

A compact layer (blocking layer) can effectively block the direct contact between the fluorine-doped tin oxide (FTO) glass substrate and electrolyte in dye-sensitized solar cells (DSSCs). The TiCl 4 hydrolysis has been widely adopted for preparing the TiO 2 compact layer (H-TiO 2 ). However, the TiCl 4 aqueous solution is unstable for its high reactivity. To improve the chemical stability of TiCl 4 aqueous solution, the Ti 4+ is encapsulated by the polymer, polyethyleneimine (PEI). Experimentals show that the Ti-PEI precursor solution can maintain their initial performances for several months. The resulting TiO 2 film (P-TiO 2 ) grown by the Ti-PEI precursor is dense, smooth and uniform without any visible and detectable cracks or voids. The P-TiO 2 compact layer is even denser than the H-TiO 2 compact layer, suggesting reducing the electron recombination and prolonging the electron lifetime in dye-sensitized solar cells. Indeed, the electron lifetime of the DSSC based on the P-TiO 2 is 13.15 ms, which is longer than the 10.83 ms based on H-TiO 2 . Meanwhile, the power conversion efficiency of the DSSC based on P-TiO 2 compact film is about 12.5% higher than that based on H-TiO 2 . Therefore, this encapsulation technology can not only improve the stability of the metal ions solution but also meet a large-scale fabrication demand of the TiO 2 compact layer in future DSSCs. [ABSTRACT FROM AUTHOR]

[Display omitted] • The metal ions doped Bi 2 O 3 nanofibres with a novel morphology are prepared. • The photocatalytic performance of Bi 2 O 3 were enhanced through doping strategy. • Co2+ doped Bi 2 O 3 exhibits great photocatalytic activity on moxifloxacin degradation. • The main active species are h+ and the three degradation pathways are proposed. Photocatalytic degradation technology is a potential way to remove organic pollutants from water. In this study, Bi 2 O 3 nanofibres doped with different metal ions (Co2+, Ni2+, and Zn2+) were fabricated successfully using the electrospinning method for use as photocatalysts. Compared to pure Bi 2 O 3 nanofibres, the energy band gap and the recombination rate of photogenerated carriers were reduced in Co2+-doped Bi 2 O 3 nanofibers, which significantly improved the photocatalytic performance of the Bi 2 O 3 nanofibres. Typically, the moxifloxacin degradation rate was 98.2% after 70 min irradiation over Co2+-doped Bi 2 O 3. Although h+, ∙O 2 –, and ∙OH were detected in the photocatalytic process, the dominant active species was h+. In addition, three degradation pathways containing 12 intermediates were proposed. [ABSTRACT FROM AUTHOR]

Abstract: A stable organic solar cell with structure of ITO/buffer/donor/acceptor/cathode is presented. A thin layer (5nm) of MoO3-doped CuPc is adopted as the buffer in CuPc/C60 organic heterojunction photovoltaic (PV) solar cells, resulting in two times longer lifetime. The surface morphology of buffer layer plays a decisive role in improving the stability. [Copyright &y& Elsevier]

• The optimized MoCoSe x @NC is prepared by a facile two-step method. • The uniform NC provides the growth space and fast electron transfer of active sites. • Mo doping can improve the intrinsic activity of CoSe x for HER. • The obtained MoCoSe x @NC exhibits excellent activity and stability for HER. Transition metal selenides have attracted wide attention owing to the unique structure and electron distribution in the field of electrocatalysis. However, adopting the suitable strategy to further improve the intrinsic activity and exposure of transition metal selenides is still a challenge. Herein, the optimized MoCoSe x encapsulated in N–doped hollow carbon nanosphere (MoCoSe x @NC) has been synthesized for hydrogen evolution reaction (HER) through a simple two–step method. Firstly, the uniform porous NC has been obtained through carbonization at 900 °C, which provides the growth space and fast electron transfer of active sites. Secondly, the optimized MoCoSe x @NC with excellent dispersion has been synthesized through the following hydrothermal process. Moreover, the synergistic effect of Mo doping can improve the intrinsic activity of CoSe x for HER. The obtained MoCoSe x @NC exhibited excellent low over potential of 60 mV at 10 mA cm−2 and great stability for HER. The enhanced activity may attribute to the good dispersion of MoCoSe x and NC substrate. After optimized synthesis process, we found that the first carbonization of NC is the base for constructing the good dispersion of MoCoSe x. This work provides a new design strategy for transition metal selenides supported on carbon substrate as electrocatalysts for HER. [ABSTRACT FROM AUTHOR]

• Co 3 O 4 crystals with different shapes and surface structures were synthesized. • Catalysis of the Co 3 O 4 crystals in persulfate was structure-dependent. • The Co 3 O 4 nanocubes had the highest catalytic activity in persulfate activation. • 1O 2 was dominantly contributed to the OG degradation. • The exposed plane of (1 1 1) was responsible for 1O 2 generation. Co 3 O 4 crystals with different shapes and surface structures were successfully synthesized. The shapes obtained included flower-like nanoplates (FN), nanocubes (NC), nanosheets (NS) and flake-stacked microsphere (FM). The shapes and surface structures of the Co 3 O 4 catalysts significantly affected their catalytic activity. Among the as-synthesized Co 3 O 4 catalysts, the NC sample displayed the highest catalytic activity in persulfate (PS) activation, achieving almost complete removal of 30 mg L−1 orange G (OG) within 10 min at the reaction conditions of 0.5 g L−1 catalyst and 8.0 mM PS. The excellent catalytic performance of NC sample could be ascribed to dominant exposed crystal plane and abundant surface hydroxyl groups. The electron paramagnetic resonance (EPR) and radical quenching tests demonstrated that reactive oxygen species (ROS) including sulfate radical (· SO 4 −), hydroxyl radical (· OH), superoxide radical (· O 2 –) and singlet oxygen (1O 2) were generated in the NC/PS system, while 1O 2 was dominantly attributed to the OG degradation. The exposed plane of (1 1 1) may be responsible for the generation of 1O 2. The study dedicates a novel mechanism of PS heterogeneous activation by Co 3 O 4 crystals and provides an ideal catalyst for efficient removal of organic pollutants in wastewater. [ABSTRACT FROM AUTHOR]

• Voids are introduced into AlN film grown on FSS through growth mode transition. • Dislocation filter and strain relief are achieved with the introducing of voids. • A 3 μm-thick AlN film grown on FSS using this strategy is nearly stress free. We demonstrate the achieving of high-quality AlN films on flat sapphire substrate (FSS) by introducing voids during growth. Voids are embedded into AlN epilayers through a growth-mode transition from island growth to step flow growth. Such voids significantly facilitated the underlying dislocations annihilation as demonstrated by the transmission electron microscopy (TEM) image. For the 3 μm-thick AlN film grown on FSS, the full width at half maximum of the X-ray rocking curve was 57/260 arcsec for (0 0 2)/(1 0 2) reflection and a threading dislocation density of 1.7 × 108 cm−2 was determined from plain-view TEM image. Moreover, the voids provided an additional stress relief channel in the AlN film grown on FSS, resulting in a tensile stress comparable to that of grown on nano-patterned sapphire substrate (NPSS). The measured lattice constants and Raman shift of AlN-E 2 (high) peak verified the 3 μm-thick AlN film grown on FSS is nearly stress free at room temperature. Taking advantages of the deliberately embedded voids, a crack-free and atomically flat AlN film was grown on FSS. The strategy put forward in this work to obtaining high-quality AlN films on FSS is much cost-efficient, which is believed to hold great promise for commercialization in AlN-based devices. [ABSTRACT FROM AUTHOR]

• N-doped TiO 2 @rGO nanotubes were prepared by annealing GO-coated H-titanate nanotubes in ammonia. • The composite absorbs nearly the full visible-light spectrum. • Without Pt as a cocatalyst, the H 2 production rate is as high as 720 µmol g−1 h−1. • Even one year, the surface Ti3+'s concentration exhibits no distinct decrease. Due to the merits of visible-light absorption and high conductivity, Ti3+ is a main focus among the modifications of TiO 2. However, surface Ti3+ is unstable. Herein, surface-stable Ti3+ in an N-doped rGO-coated TiO 2 nanotube sample is prepared. The N-doping introduced Ti-C bonds and an abundance of surface Ti3+, which produced several mid-gap states. These properties allow the composite to absorb nearly the full visible-light spectrum. Owing to the advantages of a broad visible-light absorption, short diffusion distance in the nanotube, and a good heterojunction, the composite exhibits a good photocatalytic activity. Under visible light and without Pt as a cocatalyst, methylene blue was degraded within 40 mins, and the H 2 production rate is as high as 720 µmol g−1 h−1. Due to the synergistic effect of N doping and Ti-C bond formation, the configuration of surface Ti3+ is stabilized by a charge-transfer resonance mechanism. The tightly coated graphene also plays a vital role in protecting the surface Ti3+. Even after storage for one year, the photocatalytic activity and the EPR signal intensity from Ti3+ paramagnetic states remain unchanged within experimental error. It suggests that the surface Ti3+ concentration, and the properties of the composite are stable with time. [ABSTRACT FROM AUTHOR]