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Abstracts Mo-based nanoparticles (MoO 2 and Mo 2 C) embedded in porous carbon matrix have been synthesized by a successive hydrothermal and thermal treatment strategy. The synthesized materials were tested for CO x -free H 2 production via ammonia decomposition. Various characterizations, including N 2 -sorption, TGA, FTIR, TEM, XRD, EDX and XPS, were employed to investigate the morphology, component and structure of fresh and used catalysts. In terms of fresh Mo@C sample, tiny Mo-based nanoparticles (3–6 nm) are homogeneously dispersed in porous carbon matrixes, which were rapidly nitridized to MoN phases during reaction process. Most of MoN species were still embedded in carbon matrixes after 25 h stability test. For comparison, MoN@C sample was achieved via temperature-programmed ammonolysis of Mo@C sample, demonstrating the formation of MoN species and enhanced activities. The ammonia decomposition activity (∼90% conversion) is obtained over MoN@C catalyst at 600 °C and 15,000 h −1 , which is higher than that of non-pretreated Mo@C catalyst. This embedded structure also endows them with a relatively stable performance even at high temperature. [ABSTRACT FROM AUTHOR]

Hierarchically structured ZnO hybridized with graphitic carbon nitride (g-CN) is introduced as a new material for non-enzymatic photoelectrochemical sensing of hydrogen peroxide (HO). It is based on the measurement of the decrease in the photocurrent produced by HO which consumes the photoinduced electrons ejected by the ZnO/g-CN composite. The g-CN has a beneficial effect in extending the band width of light absorption of ZnO into the visible region and to promote the separation of the photoinduced carriers. This results in an enhanced photocurrent and high-sensitivity. The ZnO/g-CN composite was characterized by scanning electron microscopy, transmission electron microscopy, X-ray diffractometry, X-ray photoelectron spectrometry, and UV-vis spectrophotometry. Under the optimized condition, the sensor has a linear response to hydrogen peroxide in the 1.3-79.8 nM concentration range, and the detection limit is 0.38 nM. The sensor is sensitive, selective, stable and can be fabricated at low costs. [Figure not available: see fulltext.] [ABSTRACT FROM AUTHOR]

Mn 2+ /Tb 3+ single-doped and codoped NaCaPO 4 phosphors were prepared by a high-temperature solid-state reaction method. Under ultraviolet irradiation, the NaCaPO 4 : Tb 3+ , Mn 2+ samples exhibit the typical green emission band of the Tb 3+ , as well as an red emission bands of the Mn 2+ . The red emission bands of the Mn 2+ were attributed to the energy transfer from the Tb 3+ to Mn 2+ , which has been justified through the luminescence spectra. The luminescence colors of NaCaPO 4 : Tb 3+ , Mn 2+ phosphors can be easily tuned by changing the concentration of Mn 2+ . These results suggest that these phosphors can be explored for near ultraviolet LED. [ABSTRACT FROM AUTHOR]

Using density-functional theory (DFT) calculations within the generalized gradient corrected approximation, the models that nonmetallic impurities X (X = C, N, S, F) substituted for O or Ti sites in anatase TiO 2 were investigated. By calculating the formation energy of X-monodoped TiO 2 with X substituted for O, we suggested that X dopants existed as C 4− , N 3− , S 2− and F − ions, respectively. Meanwhile, the X dopants existed as C 4+ , N 3+ , and S 6+ for X-monodoped (X = C, N, S) TiO 2 with X substituted for Ti. The conclusion of the valence states of nonmetallic impurities X substituted for O or Ti sites in TiO 2 is also supported by the results of optimized cell parameters and the local structures. Furthermore, an effective nonmetallic passivated codoping approach to modify the band edges of TiO 2 is proposed. Based on the first-principle calculations, we suggested that nonmetallic passivated groups such as (S 2− + C 4+ ) and (C 4− + S 6+ ) could reduce the band gap largely and make less perturbation in conduction band minima (CBM), thus lead to an ideal visible-light absorption region without affecting the reducing power. This work provides some new results and is anticipated to give some inspiration and guidance for design visible-light-driven TiO 2 photocatalyst with high efficiency. [ABSTRACT FROM AUTHOR]

[Display omitted] • An Z-scheme heterojunction has been successfully developed. • CPDs/ZIS heterostructure improves the light capture and charges life. • The CPDs highly promotes the photocatalytic hydrogen evolution of ZIS. • DFT calculations indicated a decrease in the H* adsorption's free energy. To effectively separate electron-hole pairs produced by light, a heterojunction arrangement can be employed, thereby improving photocatalytic efficiency. In this study, a simple hydrothermal process is used to manufacture carbonized polymer dots/ZnIn 2 S 4 (CPDs/ZIS) heterostructure, which enhances the light absorption and charge carrier lifetime in comparison to bare ZnIn 2 S 4 (ZIS). Upon irradiation with visible light, the 3-CPDs/ZIS composite generates hydrogen at a rate of 133 μmol g−1 h−1, which is 8.9 times faster than that of pure ZIS. The addition of CPDs can increase the range of light that can be absorbed, extend the service life of the optical charge, increase the specific surface area, and promote charge separation and transmission, which could effectively accelerate the photocatalytic reduction reaction. The presence of CPDs results in the introduction of multiple transition energy states and a decrease in the H* adsorption free energy, which enhances the hydrogen evolution activity according to the theoretical calculation findings of density functional theory (DFT) and Gibbs free energy of the hydrogen evolution process. Combining theoretical calculations and experimental results, a direct Z-type heterojunction mechanism is proposed for the hydrogen evolution promotion effectiveness of CPDs/ZIS under visible light. [ABSTRACT FROM AUTHOR]

Abstract Proton conducting solid oxide fuel cells (SOFC) show great potential to be applied in electricity generation at intermediate temperature range, attracting the efforts of developing cathode material to further improve the power density by promoting the oxygen reduction reaction. An A-site deficient layered perovskite (PrBa) 0.95 (Fe 0.9 Mo 0.1) 2 O 5+δ (PBFM) is synthesized as cathode material for BaCe 0.7 Zr 0.1 Y 0.2 O 3 (BCZY) based SOFC. A nanostructured composite electrode is fabricated by infiltrating another cobalt-based perovskite oxide of Sm 0.5 Sr 0.5 CoO 3-δ into PBFM porous structure aiming at improving the overall catalytic reaction towards oxygen reduction. After confirming the chemical compatibility between these two materials, the electrochemical performances of the single cells are measured. With loading amount of 10% Sm 0.5 Sr 0.5 CoO 3-δ Nanoparticles, a peak power density of 532 mW cm−2 is achieved at 700 °C comparing with 359 mW cm−2 for bare PBFM electrode. A short-term stability confirms the durability of this composite electrode in practical working conditions. Highlights • A novel Layered Perovskite Cathode is evaluated for proton-conducting SOFCs. • 10. wt% Sm 0.5 Sr 0.5 CoO 3–δ is the most optimized content among all cathodes. • At 700 °C, a maximum power density of 532 mWcm−2 is obtained. [ABSTRACT FROM AUTHOR]

Combining the strong localized surface plasmon resonance (LSPR) of metallic Ag and the chemically reactive Pt co-catalyst, the Ag–Pt bimetallic composite was prepared and then coated on the surface of the exfoliated defective graphitic carbon nitride nanosheets (C 3 N x NS) for plasmon hot electron-mediated photocatalytic H 2 evolution. Under the visible light irradiation, the sample of (1:2) Ag–Pt/C 3 N x NS exhibits the highest activity (1.25 mmol g−1 h−1), which is 35.7 and 1.7 times higher than that of Ag/C 3 N x NS and Pt/C 3 N x NS, respectively. Moreover, the apparent quantum efficiency (AQE) of (1:2) Ag–Pt/C 3 N x NS reaches 3.3% at 420 nm. The boosted photocatalytic capacity may be ascribed to the utilization of the advantages of the LSPR effect of Ag particles and the Schottky barrier between Pt and C 3 N x NS, resulting in more electrons participate in the reduction reaction to boost the photocatalytic H 2 evolution performance. [Display omitted] • Ag–Pt core-shell structure was deposited on the exfoliated defective C 3 N x nanosheets. • The Core Ag shows LSPR effect and the shell Pt acts chemically reactive co-catalyst. • The (1:2) Ag–Pt/C 3 N x NS exhibits the highest H 2 evolution rate (1.25 mmol g−1 h−1). • The AQE of the sample of (1:2) Ag–Pt/C 3 N x NS reaches 3.3% at 420 nm. • The boosted activity was attributed to the LSPR effect and the Schottky barrier. [ABSTRACT FROM AUTHOR]

It has been rarely reported the morphological control of derivatives of metal‐organic frameworks (MOFs) in hydrothermal conditions for photocatalytic applications. We report here a family of highly efficient composite photocatalysts composed of terephthalic acid/terephthalate (TPA) ligand and TiO2 with various morphologies (e. g. nanoparticles, nanosheets, and nanorods). The composites are synthesized by a simple one‐step hydrothermal method in various solvents (i. e. H2O, HF, H2SO4, HCl, and HNO3) using Ti‐based MOF (MIL‐125(Ti)) as precursor. The formation mechanism of composite materials with different morphological features is discussed. Impressively, the composite of TiO2 nanoparticles/TPA synthesized using H2O as solvent under hydrothermal condition exhibits the highest photocatalytic H2 activity among the studied materials, with a photocatalytic H2 production rate of 6.38 mmol g−1 h−1, which is approximately 7.5‐fold higher than pure TiO2 (Degussa, P25) and prominent apparent quantum efficiency (AQE) of 65 % at 365 nm. Furthermore, the mechanism of boosted photocatalytic H2 production is discussed. [ABSTRACT FROM AUTHOR]

A facile strategy was proposed to synthesize Nb-containing BaCeO 3 -based material, which is a potential electrolyte for proton-conducting solid oxide fuel cells (SOFCs), via a wet chemical route while the conventional synthesis of Nb-containing oxides relied on the solid state reaction method due to the unavailability of suitable Nb-precursors such as Nb-nitrates resulting in a less desirable fuel cell performance when used as an electrolyte. The BaCe 0.7 Nb 0.1 Y 0.2 O 3 − δ (BCNY) electrolyte material in this study persisted a good chemical stability against CO 2 and exhibited good performance in the fuel cell application. The fuel cell with BCNY electrolyte film showed a high performance of 533 mW cm − 2 at 700 °C. This cell performance based on BCNY electrolyte was superior to that of many stable modified BaCeO 3 -based proton-conducting SOFCs where the electrolytes were tailored by other strategies. This result indicated that the strategy presented in this study could be an effective way to prepare a stable electrolyte for high performance proton-conducting SOFCs, which could advance the development of proton-conducting SOFCs. [ABSTRACT FROM AUTHOR]

Introducing piezoelectric materials with the built-in electric field caused by mechanical force has been confirmed as an effective strategy to boost the separation efficiency of photoexcited charge carriers that determines the photocatalytic performance. In this study, we introduced Bi4Ti3O12 with superior piezoelectric properties into BiVO4–Bi4V2O10 materials to synthesize a 2D Bi4Ti3O12–BiVO4–Bi4V2O10 photocatalyst via a facile hydrothermal method. Compared with bare BiVO4, the Bi4Ti3O12–BiVO4–Bi4V2O10 piezo-photocatalytic activity towards Cr(VI) removal and oxygen evolution is boosted remarkably under both illumination and ultrasound treatments. The promoted photocatalytic activity can be ascribed to the accelerated photoexcited carrier separation efficiency driven by the polarization electric field and the synergy effect in the heterostructure. This work provides a simple and sustainable strategy for the design and development of piezo-photocatalysts with high photoredox activity capacity. [ABSTRACT FROM AUTHOR]

[Display omitted] • A dual p-n heterojunction composed of NiCo 2 O 4 /NiO/Al: SrTiO 3 was fabricated. • The dual p-n heterojunction was constructed with electrostatic adsorption force. • MOF-derived NiCo 2 O 4 /NiO was used as the O 2 -producing co-catalyst for water splitting. • The property of dual p-n heterojunction is superior to the single p-n heterojunction. • The built-in electric field contributes to the enhanced photocatalytic performance. In this study, NiCo 2 O 4 /NiO/Al: SrTiO 3 (labeled as NCO/NO/ASTO) with dual p-n heterojunction structure was devised and in-situ fabricated for the first time, in which metal–organic framework (MOF)-derived NiCo 2 O 4 /NiO (NCO/NO) was utilized as the O 2 -producing co-catalyst. This dual p-n heterojunction with the matching built-in electric field made it possible to separate and transfer charge carriers in a manner that was substantially more effective than the use of a single p-n heterojunction. The NCO/NO/ASTO-1 exhibits an excellent overall water splitting performance of 1.74 (H 2)/0.85 (O 2) mmol g−1h−1 when exposed to UV radiation, which is 1.3 and 2.6 times that of NiCo 2 O 4 /Al: SrTiO 3 (NCO/ASTO) and NiO/Al: SrTiO 3 (NO/ASTO) with single p-n heterojunction structure, respectively. The electrostatic adsorption force and matching built-in electric field between ASTO and NCO/NO have been demonstrated, ensuring the presence as well as the stability of the dual p-n junction and accelerating the migration of photogenerated carriers. Moreover, density functional theory (DFT) was used to offer theoretical evidence of the driving force for the interfacial charge transfer in the NCO/NO/ASTO dual p-n heterojunction, which could be attributed to the difference in the work functions (Φ) of the components of NO, NCO, and ASTO. [ABSTRACT FROM AUTHOR]

Narrowband emitters possess great potential in organic light emitting diodes (OLEDs) to achieve high color purity. However, developing highly efficient pure blue emitters with a simultaneously narrow full width at half-maximum (FWHM) value is a major challenge due to the energy-gap law and molecular stacking effect. Few efforts have focused on this challenging pursuit. Herein, an ingenious synthetic method was devised to achieve pure blue emitters incorporating bulky rigid planes as donors and highly twisted steric units as acceptors. Four emitters with aggregation-induced emission (AIE) characteristics, namely BCzPPM, BC-zPSP, IDCz-DBPM, and IDCz-BPSP, have been developed and used to fabricate non-doped devices. IDCz-BPSP achieves narrowed photoluminescence (PL) and electroluminescence (EL) with the benefit of suppressing vibronic coupling. Non-doped OLEDs based on IDCz-BPSP have achieved maximum external quantum efficiency (EQE max) of 4.61% with a FWHM of 25 nm/0.20 eV. The Commission Internationale de L'Eclairage (CIE) coordinates was (0.154, 0.059), with CIE y being superior to the standard of European Broadcasting Union (EBU) 0.06. The hybridized local and charge-transfer (HLCT) states of IDCz-BPSP have simultaneously boosted the PL efficiency and exciton utilization. The EL process has even achieved exciton utilization at exceeding the theoretical limit of 25%. These results indicate that the strategy of combining bulky rigid plane donor units and steric hindrance effect is a favorable strategy for constructing emitters with narrow FWHM. [Display omitted] • A "single bond-linked" strategy for deep blue AIE emitters was proposed. • The HLCT states of IDCz-BPSP have simultaneously boosted the PL efficiency and exciton utilization. • IDCz-BPSP exhibits a narrow PL and EL FWHM of 24 nm (0.19 eV) and 25 nm (0.20 eV), respectively. • Non-doped OLEDs based on IDCz-BPSP provided ultrapure deep blue emission with CIE y ＜0.06. [ABSTRACT FROM AUTHOR]

TiO2 nanotube-based photocatalytic concrete paving block was prepared, and its mechanical properties, including compressive strength and abrasion resistance, as well as photocatalytic removal of NO, were investigated. Results indicate that the compressive strength and abrasion resistance of photocatalytic concrete paving block were obviously reinforced by TiO2 nanotubes compared with TiO2 nanoparticles, which might derive from the enhanced binding force between TiO2 nanotubes and calcium–silicate–hydrate (C–S–H) gel derived from the cement hydration. Moreover, the TiO2 nanotube-based photocatalytic concrete paving block shows the best photocatalytic removal of NO among the as-prepared samples, which might result from the enhanced adsorption property for NO gas over TiO2 nanotubes, and little change of NO conversion was found before and after polishing. Overall, TiO2 nanotubes not only contribute to the reinforcement of mechanical properties of the concrete block, but also dedicated to the enhancement of photocatalytic performance for NO purification. [ABSTRACT FROM AUTHOR]

As a visible-light photocatalyst, bismuth iodide oxide (BiOI) is widely applied in water photocatalytic pollution degradation. However, due to the inherent high recombination rate of electron−hole pairs, an efficient photocatalytic performance could realize rarely by bare BiOI, resulting in its limited practical application. In this study, a novel type-II BiOI−C 3 N 5 heterostructure was prepared by a feasible solvothermal method to inhibit the recombination of photoexcited electrons and holes. The photocatalytic activity of the heterostructure was evaluated by degradation of tetracycline (TC) and penicillin G sodium. The results showed that compared with bare C 3 N 5 and BiOI, the photodegradation efficiency of tetracycline and penicillin G sodium was remarkable improved after heterostructure formation and the BiOI−C 3 N 5 (10% wt) samples demonstrated a higher degradation efficiency. The improvement of photocatalytic degradation activities can be attributed to the formation of type-II heterostructures with a close contact. Under the synergistic effect and interface structure in BiOI−C 3 N 5 , the spatial separation and transfer of charge carriers were increased significantly, which is in favor of enhancing the photocatalytic oxidation capacity of BiOI. [Display omitted] • A new BiOI-C 3 N 5 heterostructure was successfully constructed to heighten the photocatalytic oxidation capacity of BiOI. • Synergistic effect and interfacial fusions in BiOI −C 3 N 5 were formed for accelerating the charge carriers transfer. • The BiOI−C 3 N 5 heterostructures exhibit remarkable tetracycline (TC) and sodium penicillin G degradation performances. [ABSTRACT FROM AUTHOR]

It is an effective strategy to improve photocatalytic degradation performance by constructing step scheme (S-scheme) heterojunction photocatalysts with superior photo-redox capacity and high charge transfer efficiency. In this study, a series of two-dimensional/two-dimensional (2D/2D) La 2 Ce 2 O 7 /g-C 3 N 4 (LCO/CN) S-scheme heterojunction photocatalysts were synthesized via in-situ solid-phase sintering by regulating the mass ratio of raw materials. The large junction area between La 2 Ce 2 O 7 nanosheets and ultra-thin graphitic carbon nitride (g-C 3 N 4) endows the composite with significantly enhanced separation and transfer efficiency of photogenerated carriers within a satisfactory light response region. The LCO/CN-2 composite not only shows the highest photocatalytic activity with a reaction rate constant of 0.02701 min−1 to degrade Rhodamine B (RhB) under visible light irradiation for 90 min but also demonstrates stable reusability after four runs. Moreover, based on the Mott-Schottky calculations, radical trapping experiments, and ESR analysis,·O2- and·OH are identified as the main active species, and an S-scheme charge transfer mechanism is suggested to explain the enhanced photocatalytic activity. This work inspires the application of fluorite-type photocatalysts to wastewater purification and environmental restoration. [Display omitted] • La 2 Ce 2 O 7 /g-C 3 N 4 2D heterojunction photocatalyst was successfully synthesized. • The dual active species synergistically degraded RhB pollutants. • LCO/CN-2 shows a reaction rate constant of 0.02701 min−1 under visible light. • La 2 Ce 2 O 7 /g-C 3 N 4 inspires the design of fluorite-type photocatalysts. [ABSTRACT FROM AUTHOR]

In combination of a facile and scalable solvothermal method and solid-phase reduction reactions, a novel two-dimensional black TiO2 − x nanosheet (TiO2 − x NS) with high specific surface area of 108 m2 g−1 and nearly total solar spectral absorption capability have been successfully prepared. With careful characterizations, the novel TiO2 − x NS showed enhanced electrochemical performance and visible-light photocatalytic activity than those of their white TiO2 nanosheet (TiO2 NS) precursors. The black TiO2 − x NS electrode delivered a reversible specific capacity of 160 mA h g−1 even after cycling at 0.5 C (1 C = 190 mA h g−1) for 300 times, which was significantly higher than the corresponding white TiO2 NS electrode (104 mA h g−1). Meanwhile, the TiO2 − x NS also exhibited enhanced ability of visible-light photocatalytic hydrogen production than that of the white TiO2 NS. It is expected that making white TiO2 NS into black ones is an effective way to design the photocatalysts with visible light response and the anodes with long lifetime and high rate performance in lithium ion batteries. The novel black TiO2 − x NS could find potential applications in the field of environmental management and energy storage and conversion. [ABSTRACT FROM AUTHOR]

Due to the limited molecular design strategy, the development of ultrahigh color purity deep blue aggregation-induced emission (AIE) emitters with excellent photophysical and electroluminescence performances is still facing challenges at present. In this study, an effective design strategy for deep blue emitters is proposed, which can improve the performances of non-doped organic light-emitting diodes (OLEDs) by adjusting the link mode of the phenyl bridge and utilizing the steric hindrance effect of the rigid plane. Two new emitters, 3BCzPT and 4BCzPT, were obtained with phenanthroline acceptor and carbazole donor for deep blue emitting OLEDs. Particularly, 3BCzPT has been proven to have AIE characteristics through photophysical properties. Non-doped OLEDs with 3BCzPT demonstrate prominent electroluminescence (EL) performances reaching a maximum current efficiency (CEmax) of 6.3 cd A−1 and maximum external quantum efficiency (EQEmax) of 3.81%, well as ultrahigh color purity with Commission Internationale de L'Eclairage (CIE) coordinates of (0.151, 0.053). While the parameters of non-doped OLED based 4BCzPT are 4.2 cd A−1, 1.96% and (0.147, 0.082). Both emitters exhibit narrow EL spectra with the full-width at half maximum (FWHM) of 56 and 52 nm. • A strategy to construct deep blue AIE emitters with D-π-A-π-D configuration was proposed. • Highly twisted configurations are beneficial to the formation of weak intra/intermolecular interaction. • Non-doped OLEDs provided ultrapure deep blue emission with CIE x ≤0.15 and CIE y ≤0.08. • This feasible strategy can enrich the design strategy of deep blue emitters and further extend their application in OLEDs. [ABSTRACT FROM AUTHOR]

A facile one-step calcination approach for the synthesis of ordered layered N-doped KTiNbO 5 /g-C 3 N 4 (NTNO/CN) heterojunction composites was developed. It was found that KTiNbO 5 layers were in-situ doped by nitrogen atoms to form N-KTiNbO 5 and two-layered g-C 3 N 4 nanosheets were formed within the interlayers of N-KTiNbO 5 due to the space-confined effects. The photocatalytic performance of the resulted composites was evaluated by the degradation of rhodamine B (RhB) and bisphenol A (BPA) under visible light irradiation. N-KTiNbO 5 coupled with a proper amount of g-C 3 N 4 exhibited an excellent photocatalytic performance due to the synthetic effects of N doping and layered heterojunction, leading to the high efficiency of light harvesting and charge separation. Especially, the in-situ intercalated two-layered g-C 3 N 4 nanosheets can significantly increase the contact area with N-KTiNbO 5 layers for efficient charge transfer across the interface, showing a much greater effect on the enhanced photocatalytic activity than those on the pure surface of N-KTiNbO 5 . It is expected that such a layered heterojunction can greatly speed up the separation and efficient transfer of photogenerated charge carriers. The active species of O 2 − played a leading role in the photocatalytic process while h + contributed to a lesser extent during the photocatalytic degradation of RhB over NTNO/CN-1, as determined by the active species capture experiment and ESR spectra. This work provides a new insight into the preparation of layered heterojunction hybrids with ordered alternative layered structure, and thus opens up the possibility of ‘design-and-build’ 2D layered heterojunctions for large-scale theoretical exploration and practical applications. [ABSTRACT FROM AUTHOR]

Li1.6Mn1.6O4 is a representative ion sieve material that is used to recover lithium from salt brines and bitterns owing to its high lithium ion adsorption capacity reaching 11.9–44 mg g−1. However, manganese dissolution during acid treatment hinders the industrial application of the material. For investigating the mechanism of manganese dissolution, the precursor Li1.6Mn1.6O4 and ion sieve H1.6Mn1.6O4 were prepared and characterized using X-ray diffraction (XRD), scanning electron microscopy (SEM), Fourier-transform infrared spectroscopy (FT-IR), chemical content analyses, diffuse reflectance infrared Fourier-transform spectroscopy (DRIFTS), and X-ray photoelectron spectroscopy (XPS). The results of XRD, SEM, and FT-IR showed that the bulk phase of Li1.6Mn1.6O4 retained the spinel structure, whereas the lattice diminished during acid treatment. The results of chemical content analyses showed that the bulk phase of Li1.6Mn1.6O4 contained a few trivalent manganese atoms and that the mean valence of manganese in the material increased during acid treatment. DRIFTS and XPS exhibited that the surface of Li1.6Mn1.6O4 was mostly full of tetravalent manganese and retained the spinel structure during acid treatment. In the proposed mechanism of manganese dissolution, an electron of trivalent manganese in the bulk phase transfers to the surface and is captured by tetravalent manganese within the acidic environment. Then, tetravalent manganese is converted to bivalent manganese after acquiring sufficient electrons, and dissolution occurs simultaneously. [ABSTRACT FROM AUTHOR]

High-alumina-coal fly ash (HAFA) with a high Li content is regarded as a potential resource for Li production. To support the development of Li recovery technology from HAFA, the distribution and modes of occurrence of Li in HAFA were investigated. HAFA was separated into magnetic particles, glass, and mullite+corundum+quartz (MCQ) using an acid-alkali combination method. 79–94% of the Li was found in glass, with the remaining 5–16% and <5% of Li in MCQ and magnetic particles, respectively. Chemical state imaging of Li in HAFA, magnetic particles, and MCQ was obtained using time-of-flight secondary ion mass spectrometry (TOF-SIMS). Lithium was found to be relatively uniformly distributed in the HAFA particles and strongly correlated with Al and Si. Possible formation pathways of Li in the glass phase were proposed. The energy differences between reactants and products (∆E) calculated using the generalized gradient approximation (GGA) method indicated that Li occurred in Q 3 (0Al) and Q 3 (1Al) structures by reacting with Q 4 (0Al) and Q 4 (1Al). Based on the experimental and simulation results, we propose extracting Li during the pre-desilication process by dissolving the glass phase. [ABSTRACT FROM AUTHOR]

High-alumina coal fly ash (HAFA) is a special solid waste due to the existence of more than 45% alumina and 35% silica, which can be applied to prepare Al-Si series ceramics if the impurities can be removed and the Al/Si mass ratio can exceed 2.55 (Mullite: 3Al 2 O 3 .2SiO 2 ). In this work, a new mechanical–chemical synergistic activation–desilication process is proposed, and the contents of different impurities can be lowered up to less than 1%, and the Al/Si mass ratio can be elevated from 1.26 to 2.71. Especially, the mechanism of this process is investigated in detail. The analysis of the mechanism shows that the decrease of Q 4 (3Al) and the increase of Q 4 (0Al), Q 4 (1Al), and Q 4 (2Al) improve amorphous silicate reactivity through synergistic activation, and the exposed amorphous Si-O-/Si-O-Si can be removed by OH- during the desilication process (desilicated ratio>55%), which help the fine mullite to exhibit excellent properties (bulk density > 2.85 g/cm 3 , apparent porosity < 0.5%) during the sintering process. Finally, this process not only decreases the pollution but also alleviates the shortage of Al/Si resources and promotes the clean development of coal-fired power generation. [ABSTRACT FROM AUTHOR]

Electricity and water from renewable hydropower plant are used as input for electrolysis unit to generate hydrogen, while CO 2 is captured from 600 MW supercritical coal power plant using post-combustion chemical solvent based technology. The captured CO 2 and H 2 generated through electrolysis are used to synthesize methanol through catalytic thermo-chemical reaction. The methanol synthesis plant is designed, modeled and simulated using commercial software Aspen Plus ® . The reactor is analyzed for two widely adopted kinetic models known as Graaf model and Vanden-Bossche (VB) model to predict the methanol yield and CO 2 conversion. The results show that the methanol reactor based on Graaf kinetic model produced 0.66 tonne of methanol per tonne of CO 2 utilized which is higher than that of the VB kinetic model where 0.6 tonne of methanol is produced per tonne of CO 2 utilized. The economic analysis reveals that 1.2 billion USD annually is required at the present cost of both H 2 production and CO 2 abatement to utilize continuous emission of 3.2 million tonne of CO 2 annually from 600 MW supercritical coal power unit to synthesize methanol. However, sensitivity analysis indicates that methanol production becomes feasible by adopting anyone of the route such as by increasing methanol production rate, by reducing levelised cost of hydrogen production, by reducing CO 2 mitigation cost or by increasing the current market selling price of methanol and oxygen. [ABSTRACT FROM AUTHOR]

A novel mitochondria-targeted ratiometric two-photon fluorescent probe ( Mito-MQ ) for detecting intracellular cysteine (Cys) and homocysteine (Hcy) has been designed. Mito-MQ showed the ratiometric fluorescent detection signal (the green-to-blue emissionfrom 517 nm to 460 nm) to cysteine (Cys) and homocysteine (Hcy) over glutathione (GSH), along with the fast response rate (10 min). The detection mechanism was illustrated by 1 H NMR, ESI-MS and theoretical calculation. The co-localization coefficient of 0.87 between Mito-MQ and MitoTracker Red revealed that the probe was predominantly present in mitochondria, therefore, Mito-MQ was successfully applied to detect mitochondrial oxidative stress by detecting the change of Cys/Hcy. Moreover, imaging in fresh tissue slices indicated that Mito-MQ could work in deep tissue (ca. 130 µm) under two-photon excitation. Furthermore, the measurement of Cys/Hcy detection in zebrafish showed that probe can be used in determination of biothiols in vivo. [ABSTRACT FROM AUTHOR]

A reasonable and economic process to achieve the comprehensive utilization of waste from production of zirconium oxychloride would benefit sustainable development of zirconium industries and reduce environmental pollution. In this paper, wollastonite was prepared from spent caustic liquor and zirconium-containing silicon slag at low temperature. The effects of CaO/SiO 2 mole ratio, reaction temperature, reaction time, and rotation rate on the crystallization and morphology of wollastonite were systemically investigated. The optimal conditions for desilication were confirmed as a CaO/SiO 2 mole ratio of 1.0, a reaction temperature of 90 °C, a desilication time of 60 min, and a rotation rate of 200 r/min. Wollastonite was subsequently prepared by calcination of the obtained calcium silicate hydrate at 1000 °C for 1.0 h. The developed process achieved good performance of wollastonite and alkali liquor with a low silicate content, which met the standard of an industrial-grade product. [ABSTRACT FROM AUTHOR]

Zirconia fiber, with its resistance to ultra-high temperature, is irreplaceable in many applications. Herein, a technique combining the sol-gel method and electrospinning was used to fabricate uniform 1D zirconia nanofibers from zirconium polyacetate. A suitable heat treatment process was established, and the effects of spinning parameters and additives on the fiber morphology were investigated using XRD, SEM, TGA, and FTIR. The results showed that addition of silica effectively inhibited grain growth and reduced the grain size to 30–60 nm. By optimizing the electrospinning parameters and the sintering process, fine-grained tetragonal zirconia fibers of 400–700 nm diameter could be produced. [ABSTRACT FROM AUTHOR]

[Display omitted] • An all-organic S-scheme heterojunction has been successfully developed. • The heterojunction contains a D-A type conjugated polymer and C 3 N 4 nanosheets. • The interfacial heterojunction was fabricated via a π-π conjugated interaction. • DFT calculations indicated the formed built-in electric field drove charge transfer. • The optimal P 2 CNNS exhibits photocatalytic H 2 evolution rate of 50.2 mmol·g−1 h−1. Designing an excellent photocatalyst with high space separation efficiency of photogenerated carriers to boost the rate of photocatalytic hydrogen (H 2) generation remains a challenge. In this work, the S-scheme heterojunction containing a donor–acceptor (D-A) type conjugated polymer of PyDTDO-3 and a two-dimensional (2D)-layered conjugated polymer of C 3 N 4 nanosheets with conjugated heptazine units (denoted as PCNNS) was prepared for photocatalytic H 2 production. It is found that the recombination rate of photogenerated electron-hole pairs is decreased by the S-scheme heterojunction structure through establishing an intimate π–π conjugated heterointerface between PyDTDO-3 and C 3 N 4 NS. To clarify the potential photocatalytic mechanism, diversified characterization techniques were employed and the density functional theory (DFT) calculations were conducted. As a result of the difference in the work function, a Fermi level gap is formed between PyDTDO-3 and C 3 N 4 , which eventually leads to the band edge bent upward/downward and the presence of the built-in electric field causing the spontaneous interfacial charge transfer from C 3 N 4 NS to PyDTDO-3 at the π–π conjugated interface. Owing to its unique structure and optical properties, the optimal P 2 CNNS heterojunction photocatalyst shows excellent photocatalytic H 2 generation performance, which reaches a maximum of 50.2 mmol g−1 h−1 under visible illumination. [ABSTRACT FROM AUTHOR]

High-alumina coal fly ash (HAFA) is a special solid waste because it contains more than 45% alumina and 35% silica. This material can be applied to prepare Al–Si series ceramics if the impurities can be removed and the Al/Si mass ratio can be elevated to a high level. In this work, a new mechanical–chemical synergistic activation–desilication process is proposed and optimized. During the synergistic activation, the morphology, ironic leaching ratios, efficient desilicated ratio (EDR), and mineral phases of different treatments are investigated. The reactivity of amorphous silica can be elevated to a high level (EDR>11%). After the desilication process, the contents of different impurities can be lowered up to less than 1%, and the Al/Si mass ratio can be elevated from 1.26 to 2.71. Mullite refractories are prepared from desilicated HAFA by forming and sintering process, and the bulk density and apparent porosity can reach to 2.85 g/cm 3 and 2.07%, respectively. [ABSTRACT FROM AUTHOR]

The first two-photon fluorescent probe ( PC ) for selectively detecting biological Cu (Ⅱ) and pyrophosphate (PPi) has been developed based on 7-substituted coumarin in this study. The probe presented excellent selective two-photon “on-off-on” detection signal for Cu(II) /PPi in aqueous solution. The two-photon detection ensemble ( PCCu ) can detect PPi released from DNA amplification after the polymerase chain reactions (PCR). The probe showed low cytotoxicity and good biocompatibility, and therefore can be applied for imaging Cu(II)/PPi in living cells under two-photon excitation. Furthermore, the ensemble probe ( PCCu ) was also used to image PPi in deep living rat tissues (~100 µm) and in 5-days old zebrafish. [ABSTRACT FROM AUTHOR]

A two-photon fluorescent probe ( DMPCA ) for the detection of bisulfite anion in water was developed based on twisted-intramolecular-charge-transfer (TICT) mechanism. Fluorescence intensity of DMPCA increased dramatically (65 fold) upon the addition of HSO 3 − . The two-photon absorption cross-section of DMPCA was found to be 725 GM at 700 nm upon the addition of HSO 3 − . The fluorescent probe showed an excellent selectivity for bisulfite anion over other anions. The nucleophilic addition reaction mechanism with aldehyde was confirmed with NMR and MALDI-TOF. The TICT detection mechanism was confirmed by viscosity-dependent fluorescence spectra and time resolved fluorescence spectra. Moreover, DMPCA was successfully applied to the detection of bisulfite anion in HeLa cells with low cytotoxicity under two-photon excitation. [ABSTRACT FROM AUTHOR]

A two-photon fluorescent probe ( NQ ) for cysteine (Cys) and homocysteine (Hcy) was developed based on twisted-intramolecular-charge-transfer (TICT) mechanism. NQ showed excellent “OFF–ON” fluorescence (at 540 nm) detection signal on addition of Cys/Hcy with high selectivity. The detection mechanism was successfully proved by theoretical calculations, viscosity dependent fluorescence and time resolved fluorescence spectra. NQ exhibits large two-photon absorption (TPA) cross-section with Cys/Hcy (580 and 710 GM) at nearly 800 nm, respectively. Cell-culture results indicated that NQ was cell-permeable and could be used to detect Cys/Hcy with low cytotoxicity under two-photon excitation in living cells. To our best knowledge, NQ is the first TICT based two-photon fluorescent probe for Cys/Hcy. [ABSTRACT FROM AUTHOR]

[Display omitted] • [Mo 3 S 13 ]2− nanoclusters are highly dispersed into the micropores of TpPa-1-COF. • The size and micro-environment of micropores play a central role in anchoring MS-c. • The photocatalytic H 2 evolution rate of MS-c@TpPa-1 is increased by 4.7 times. • The coordinated Mo − N groups between MS-c and TpPa-1-COF result in enhanced stability. • The favorable electron–proton transfer to form H* occurs on the S instead of N sites. Non-noble-metal-based [Mo 3 S 13 ]2− nanoclusters (MS-c) as a co-catalyst face the problems of instability and inevitable aggregation, which limit its photocatalytic applications. Herein, β-ketoenamine-linked covalent organic framework (COF), namely TpPa-1-COF, was utilized to embed MS-c. The micropores of TpPa-1-COF could not only limit the growth of MS-c to achieve its high dispersion but also play a central role in anchoring MS-c. Moreover, the structural stability of MS-c is highly enhanced due to the confinement effect of TpPa-1-COF, and the visible-light-driven photocatalytic H 2 evolution rate of 528 μmol g−1h−1 for MS-c@TpPa-1 (0.3: 1), which is increased by 4.7 times as compared with that of TpPa-1-COF. The density functional theory (DFT) calculations indicate that the electrons transfer from TpPa-1 to MS-c occurs at the interface of MS-c@TpPa-1 in the ground state based on the charge density difference analysis. With the irradiation of visible light, the photoexcited electrons derived from the π-conjugated TpPa-1-COF backbone could be delivered to the embedding MS-c through the coordinated Mo − N groups, and the favorable electron–proton transfer to form H* and efficient desorption of H 2 occurs on the S sites instead of N sites in MS-c@TpPa-1, resulting in the enhanced photocatalytic H 2 evolution rate. Overall, this work provides a novel approach for embedding the unstable MS-c with low cost into the micropores of COF via coordination bonds to improve the structural stability and photocatalytic activity. [ABSTRACT FROM AUTHOR]

[Display omitted] • [Mo 3 S 13 ]2− nanoclusters are highly dispersed into the micropores of TpPa-1-COF. • The size and micro-environment of micropores play a central role in anchoring MS-c. • The photocatalytic H 2 evolution rate of MS-c@TpPa-1 is increased by 4.7 times. • The coordinated Mo − N groups between MS-c and TpPa-1-COF result in enhanced stability. • The favorable electron–proton transfer to form H* occurs on the S instead of N sites. Non-noble-metal-based [Mo 3 S 13 ]2− nanoclusters (MS-c) as a co-catalyst face the problems of instability and inevitable aggregation, which limit its photocatalytic applications. Herein, β-ketoenamine-linked covalent organic framework (COF), namely TpPa-1-COF, was utilized to embed MS-c. The micropores of TpPa-1-COF could not only limit the growth of MS-c to achieve its high dispersion but also play a central role in anchoring MS-c. Moreover, the structural stability of MS-c is highly enhanced due to the confinement effect of TpPa-1-COF, and the visible-light-driven photocatalytic H 2 evolution rate of 528 μmol g−1h−1 for MS-c@TpPa-1 (0.3: 1), which is increased by 4.7 times as compared with that of TpPa-1-COF. The density functional theory (DFT) calculations indicate that the electrons transfer from TpPa-1 to MS-c occurs at the interface of MS-c@TpPa-1 in the ground state based on the charge density difference analysis. With the irradiation of visible light, the photoexcited electrons derived from the π-conjugated TpPa-1-COF backbone could be delivered to the embedding MS-c through the coordinated Mo − N groups, and the favorable electron–proton transfer to form H* and efficient desorption of H 2 occurs on the S sites instead of N sites in MS-c@TpPa-1, resulting in the enhanced photocatalytic H 2 evolution rate. Overall, this work provides a novel approach for embedding the unstable MS-c with low cost into the micropores of COF via coordination bonds to improve the structural stability and photocatalytic activity. [ABSTRACT FROM AUTHOR]

It is still challenging to fabricate photocatalysts via loaded metal cocatalysts with good dispersion onto the conjugated polymers (CPs). Herein, a donor-acceptor (D–A) structural CP of PyDTDO-3 was employed to host platinum (Pt) nanoparticles (NPs) using N , N ′-dimethylformamide (DMF) as a protectant, stabilizer, and reducing agent, which not only promotes Pt NPs to have excellent dispersion property on the surface of PyDTDO-3 but also endows Pt NPs to maintain metallic Pt0 species. As a result, the PyDTDO-3 loaded with Pt NPs exhibits remarkable hydrogen (H 2) evolution activity with a rate of 39.9 mmol g−1 h−1 under visible light irradiation, and the fair stability of optimal 7% Pt/PyDTDO-3 is expressed in the rate of H 2 generation upon 30 h cycling. Based on density functional theory (DFT) calculations, it has been demonstrated that Pt NPs are selectively loaded onto the acceptor (A) unit of PyDTDO-3 that has the lowest adsorption energies (E ads) and the closest bond lengths between the Pt NPs and PyDTDO-3. Moreover, there are much more electrons filling at the Fermi level (E f), indicating the optimal 7% Pt/PyDTDO-3 with high electroconductivity timely captured and removed the photoinduced electrons and thus realized the space separation efficiency of electron-hole pairs. Overall, our findings offer a rational way to load metal cocatalysts onto CPs with good dispersion for efficient photocatalytic H 2 evolution. [Display omitted] • Well-dispersed Pt NPs are fabricated onto the conjugated D-A type polymers. • DMF was used as a protectant, stabilizer, and reducing agent to obtain metallic Pt0. • Pt (111) plane is selectively loaded onto the acceptor (A) unit of PyDTDO-3. • The photoinduced electrons transfer from D to A unit of PyDTDO-3 and then to Pt NPs. • The optimal 7% Pt/PyDTDO-3 exhibits photocatalytic H 2 rate of 39.9 mmol g−1 h−1. [ABSTRACT FROM AUTHOR]

A hydrothermal method was employed to synthesize the novel 2D/2D BiOCl/H+Ti 2 NbO 7 − heterojunction photocatalysts, showing the improved photocatalytic RhB degradation efficiency. • 2D/2D BiOCl/H+Ti 2 NbO 7 − heterojunction was synthesized by a hydrothermal route. • 2D/2D heterostructure facilitated the efficient charge separation and transfer. • BiOCl/H+Ti 2 NbO 7 − showed the high photoactivity due to heterojunction formation. • The h+ and •O 2 − played a crucial role in RhB photodegradation. To realize highly efficient removal of organic pollutant is a hot spot in environmental and energy science. Herein, we firstly prepared re-stacked H+Ti 2 NbO 7 − nanosheets (HTN) to fabricate the novel two-dimensional (2D)-2D BiOCl/H+Ti 2 NbO 7 − (BHT) heterojunctions by a hydrothermal method. The HTN were well combined with BiOCl nanoplates with an intimate interface to form a heterostructure. The rhodamine B (RhB) molecules were used as a target pollutant to evaluate the photocatalytic performance of samples under visible light. All BHT composites, with an optimal sample of BHT-4, showed the improved photocatalytic activity for degradating RhB compared with the single BiOCl and HTN. The enhanced activity was mainly attributed to the efficient charge separation and transfer, which was resulted from the formation of heterojunction between BiOCl and HTN. The produced active species can be detected by trapping experiments and ESR spectra. It indicated that hole (h+) and superoxide radical (O 2 −) played a crucial role in the photocatalytic RhB degradation, while hydroxyl radical (OH) contributed a little. A possible photodegradation mechanism was also discussed based on the corresponding experimental results. This work provides an insight for preparing 2D/2D heterojunctions with a high photocatalytic activity. [ABSTRACT FROM AUTHOR]

Herein, we report a one-dimensional (1D) S-doped K3Ti5NbO14@TiO2 (STNT) core-shell heterostructured composite with an enhanced photocatalytic degradation activity under visible light, which was prepared by a simple reassembly-calcination method using thiourea as the S source. The anisotropically shaped rods are favorable for the rapid transport of photogenerated charge carriers. The substitution of Ti4+ by S6+ is primarily incorporated into the lattice of the TiO2 shell so as to create an intra-band-gap state below the conduction band (CB) position, giving rise to Ti−O−S bonds and thus the visible light response. The presence of electron-deficient S atoms is of benefit to the decreased recombination rate of photogenerated electrons and holes by capturing electrons (e−). Meanwhile, a tight close interface between K3Ti5NbO14 and TiO2 was formed to achieve a nano-heterojunction structure, leading to the fostered separation of its interfacial photogenerated electrons and holes. The visible-light-driven photocatalytic degradation of methylene blue (MB) by STNT composites is higher than that by pure K3Ti5NbO14, owing to the synergistic effects of S doping and heterojunction. A possible photocatalytic mechanism was proposed with a reasonable discussion. This work may provide an insight into constructing highly efficient core-shell photocatalysts used toward sustainable environmental remediation and resource shortages. [ABSTRACT FROM AUTHOR]

A novel N-doped K3Ti5NbO14@TiO2 (NTNT) core-shell heterojunction photocatalyst was synthesized by firstly mixing titanium isopropoxide and K3Ti5NbO14 nanobelt, and then calcinating at 500 °C in air using urea as the nitrogen source. The samples were analyzed by X-ray diffraction pattern (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), UV-Vis absorption spectroscopy and X-ray photoelectron spectroscopic (XPS) spectra. Anatase TiO2 nanoparticles were closely deposited on the surface of K3Ti5NbO14 nanobelt to form a nanoscale heterojunction structure favorable for the separation of photogenerated charge carriers. Meanwhile, the nitrogen atoms were mainly doped in the crystal lattices of TiO2, resulting in the increased light harvesting ability to visible light region. The photocatalytic performance was evaluated by the degradation of methylene blue (MB) under visible light irradiation. The enhanced photocatalytic activity of NTNT was ascribed to the combined effects of morphology engineering, N doping and the formation of heterojunction. A possible photocatalytic mechanism was proposed based on the experimental results. [ABSTRACT FROM AUTHOR]