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As a new kind of air-hardening soil reinforcement material, polymer is being widely applied in river-bank slope reinforcement and ecological slope protection area. Thus, more attention should be paid to study the characteristics of reinforced soil after immersion. In this study, water-induced changes in strength characteristics of sand reinforced with polymer and fibers were reported. Several factors, including polymer content (1%, 2%, 3% and 4% by weight of dry sand), immersion time (6, 12, 24 and 48 h), dry density (1.40, 1.45, 1.50, 1.55 and 1.60 g/cm3,) and fiber content (0.2%, 0.4%, 0.6% and 0.8% by weight of dry sand) which may influence the strength characteristics of reinforced sand after immersion were analyzed. The microstructure of reinforced sand was analyzed with nuclear magnetic resonance (NMR) and scanning electron microscope (SEM). Experimental results indicate that the compressive strength increases with the increase of polymer content and decreases with the increase of immersion time; the softening coefficients decrease with the increase of the polymer content and immersion time and increase with an increment in density and fiber content. Fiber plays an active role in reducing water-induced loss of strength at 0.6% content.

Reduction of bromate to bromide is of great significance for the remediation of bromate-containing waters. In natural water, some low-molecular-weight organics (LMWOs) ubiquitously coexist with bro...

Prostaglandin D2 (PGD2) is the most abundant prostaglandin in the brain, but its involvement in brain damage caused by type 2 diabetes (T2D) has not been reported. In the present study, we found that increased PGD2 content is related to the inhibition of autophagy, which aggravates brain damage in T2D, and may be involved in the imbalanced expression of the corresponding PGD2 receptors DP1 and DP2. We demonstrated that DP2 inhibited autophagy and promotedT2D-induced brain damage by activating the PI3K/AKT/mTOR pathway, whereas DP1enhanced autophagy and amelioratedT2D brain damage by activating the cAMP/PKA pathway. In a T2D rat model, DP1 expression was decreased, and DP2 expression was increased; therefore, the imbalance in PGD2-DPs may be involved in T2D brain damage through the regulation of autophagy. However, there have been no reports on whether PKA can directly inhibit mTOR. The PKA catalytic subunit (PKA-C) has three subtypes (α, β and γ), and γ is not expressed in the brain. Subsequently, we suggested that PKA could directly interact with mTOR through PKA-C(α) and PKA-C(β). Our results suggest that the imbalance in PGD2-DPs is related to changes in autophagy levels in T2D brain damage, and PGD2 is involved in T2D brain damage by promoting autophagy via DP1-PKA/mTOR and inhibiting autophagy via DP2-PI3K/AKT/mTOR.

Cesium lead halide perovskite nanocrystals (NCs) have compelling photoelectric properties while their poor stability severely impedes their practical applications. Herein, we demonstrate novel CsPbBr3–CsPbBr3 homostructured NCs induced by a thioacetamide-oleylamine (TAA-OAm) ligand system via a facile room temperature re-precipitation method. The TAA-OAm ligand system could form long-chain N-substituted thioamides and short-chain S2− ligands, resulting in two different growth rates of CsPbBr3 NCs and finally forming CsPbBr3–CsPbBr3 homostructured NCs. The performed structural and compositional characterizations corroborate the existence of CsPbBr3–CsPbBr3 homostructured NCs. The obtained CsPbBr3–CsPbBr3 homostructures exhibit green emission of 510 nm and superior stability at room temperature in air. Our study provides a new approach to improve the stability of halide perovskite NCs, which may pave the way for future optoelectronic applications.

Polydopamine (PDA), which is a mussel-inspired synthetic polymer, is widely used in surface modification field because of the high potential of the dopamine functional groups. Herein, we develop an SnO2 nanocontainer and deposit polypyrrole (PPy), molybdate corrosion inhibitors and PDA layers using the layer-by-layer self-assembly technology. Then, the SnO2 nanocontainer were incorporated into the epoxy coating to improve their corrosion resistance and self-healing ability and realize the active corrosion protection of stainless steels. The XRD, FTIR, TGA and Zeta potential results confirm the deposition of each layer on the surface of the SnO2 nanocontainer. The FESEM and HRTEM images confirm the formation of the core-shell structures on the SnO2 nanocontainers. The ICP-MS test indicates the slow-release tendency of the encapsulated molybdate corrosion inhibitors the in neutral environments. Further, the corrosion behaviors of the epoxy-based coatings with/without 10 wt% SnO2 nanocontainers are evaluated using electrochemical tests in 3.5 wt% NaCl solution. Results suggest that epoxy coatings with PDA-decorated SnO2 nanocontainers exhibit a high corrosion resistance and an excellent self-healing performance. The enhanced anti-corrosion and self-healing properties of the epoxy coatings can be attributed to the deposited PDA layer on the SnO2 nanocontainer, which serves as a pH-sensitive gatekeeper that can control the on-demand release of the molybdate corrosion inhibitor and promote the reformation of the cracked polymer networks using the dopamine functional groups and iron oxide. Furthermore, various OH groups provided by PDA facilitates the dispersion of the SnO2 nanocontainers in epoxy coatings. The application of multi-functional dopamine-based gatekeepers will allow more applications with respect to multi-functional intelligent anti-corrosive coating formulations.

The billions of tons of mineral dust released into the atmosphere each year provide an important surface for reaction with gas-phase pollutants. These reactions, which are often enhanced in the presence of light, can change both the gas-phase composition of the atmosphere and the composition and properties of the dust itself. Because dust contains titanium-rich grains, studies of dust photochemistry have largely employed commercial titanium dioxide as a proxy for its photochemically active fraction; to date, however, the validity of this model system has not been empirically determined. Here, for the first time, we directly investigate the photochemistry of the complement of natural titanium-containing minerals most relevant to mineral dust, including anatase, rutile, ilmenite, titanite, and several titanium-bearing species. Using ozone as a model gas-phase pollutant, we show that titanium-containing minerals other than titanium dioxide can also photocatalyze trace gas uptake, that samples of the same mineral phase can display very different reactivity, and that prediction of dust photoreactivity based on elemental/mineralogical analysis and/or light-absorbing properties is challenging. Together, these results show that the photochemistry of atmospheric dust is both richer and more complex than previously considered, and imply that a full understanding of the scope and impact of dust-mediated processes will require the community to engage with this complexity via the study of ambient mineral dust samples from diverse source regions.

A considerable number of engineering hazards are caused by loose internal structure of sands. Thus, many researchers have explored a variety of reinforcement methods. A new reinforcement technique was experimentally evaluated in this study. In particular, a hybrid method with a combination of fiber and polymer was studied. Three different types of fibers (sisal, polypropylene, and palm) in combination with varying concentrations of polymers were experimented to improve the internal structure and strength of sand samples reconstituted at different densities. Through a series of laboratory tests, the compressive and tensile strength variations of different combinations were obtained, and the interaction between fibers and polymer inside the sand was evaluated by scanning electron microscopy (SEM). The experimental results show that the tensile and compressive strength of the reinforced sand increases with the increase of the polymer concentration, sample density, and different fiber combinations. This provides some references for future practical engineering applications.

Ligands may increase the yields of reactive oxygen species (ROS) in zero-valent iron (ZVI)/O2 systems. To clarify the relationship between the properties of ligands and their effects on the oxidative removal of contaminants, five common ligands (formate, acetate, oxalate, ethylenediaminetetraacetic acid (EDTA), and phosphate) as well as acetylacetone (AA) were investigated with arsenite (As(III)) as the target contaminant at three initial pH values (3.0, 5.0, and 7.0). The addition of these ligands to the ZVI/O2 system resulted in quite different effects on As(III) removal. EDTA enhanced the oxidation of As(III) to arsenate (As(V)) but inhibited the removal of As(V). Oxalate was the only ligand in this work that accelerated both the removal of As(III) and As(V). By analyzing the ligand effects from the four aspects: dissolution of surface iron (hydr)oxides, corrosion of ZVI, reaction with ROS, and interference with precipitation, the following properties of ligands were believed to be important: ability to provide dissociable protons, complexation ability with iron, and reactivity with ROS. The complexation ability is a double-edged sword. It could enhance the generation of ROS by reducing the reduction potential of the Fe(III)/Fe(II) redox couple, but also could inhibit the removal of arsenic by coprecipitation. The elucidated relationship between the key property parameters of ligands and their effects on the ZVI/O2 system is helpful for the rational design of effective ZVI/ligand/O2 systems.

An experimental study was conducted to determine the characteristics of the flame spread and droplets of metal-polyethylene (PE) sandwich panels during combustion. The mass-loss rate, average flame height, temperature, and fire spread rate were investigated. The results showed that the fire spread rate, mass change of the droplets, average flame height, and temperature increased with an increase in the sample length, except for the mass loss rate of the 40 cm-long sample. The time interval between the droplets decreased, and the flame pulsation frequency increased. The relationship between the flame height and sample length was determined. During the combustion process, bending deformation and top flame phenomena occurred due to the shrinkage of the PE, which increased the fire risk. The distance between the outer surface of the expanded metal aluminum layer and the insulation panel increased with an increase in the panel length. A schematic diagram of the fire spread of the metal sandwich panel was established based on the observations and theoretical analysis. The mechanism and combustion behavior of the metal sandwich panels were determined to provide references for the construction of metal sandwich panels of exterior walls.

Nano Ru-based catalysts, including monometallic Ru and Ru-Zn nanoparticles, were synthesized via a precipitation method. The prepared catalysts were evaluated on partial hydrogenation of benzene towards cyclohexene generation, during which the effect of reaction modifiers, i.e., ZnSO4, MnSO4, and FeSO4, was investigated. The fresh and the spent catalysts were thoroughly characterized by XRD, TEM, SEM, XPS, XRF, and DFT studies. It was found that Zn2+ or Fe2+ could be adsorbed on the surface of a monometallic Ru catalyst, where a stabilized complex could be formed between the cations and the cyclohexene. This led to an enhancement of catalytic selectivity towards cyclohexene. Furthermore, electron transfer was observed from Zn2+ or Fe2+ to Ru, hindering the catalytic activity towards benzene hydrogenation. In comparison, very few Mn2+ cations were adsorbed on the Ru surface, for which no cyclohexene could be detected. On the other hand, for Ru-Zn catalyst, Zn existed as rodlike ZnO. The added ZnSO4 and FeSO4 could react with ZnO to generate (Zn(OH)2)5(ZnSO4)(H2O) and basic Fe sulfate, respectively. This further benefited the adsorption of Zn2+ or Fe2+, leading to the decrease of catalytic activity towards benzene conversion and the increase of selectivity towards cyclohexene synthesis. When 0.57 mol·L−1 of ZnSO4 was applied, the highest cyclohexene yield of 62.6% was achieved. When MnSO4 was used as a reaction modifier, H2SO4 could be generated in the slurry via its hydrolysis, which reacted with ZnO to form ZnSO4. The selectivity towards cyclohexene formation was then improved by the adsorbed Zn2+.

Monometallic Pt catalysts supported on mesoporous (MP) ZrO2 were prepared and utilized as catalysts in the aqueous-phase upgrading of lignocellulosic biomass-derived levulinic acid (LA), with formi...

Selective hydrogenation of benzene toward cyclohexene is an economically interesting and technically challenging reaction, and catalytic system design is the kernel for selective hydrogenation of b...

We proposed an agarose coated macro-bend fiber (AC-MBF) sensor for relative humidity and temperature measurement at 2 μm. Stronger resonance dips in the bent fiber sensor can be found at 2 μm region, which is at the peak of water absorption better for humidity sensing. Experimentally, such an AC-MBF sensor was very sensitive to humidity at 2 μm region. The highest sensitivity of 0.314 nm/%RH was achieved in the range of 40–95%, which was much higher than the wavelength–modulated sensors at 1.5 μm reported previously. Meanwhile, the sensor is also very sensitive to temperature. The maximum temperature sensitivity of the macro-bend fiber sensor is 5.37 nm/°C. Additionally, AC-MBF sensor is with fast response time and recovery time of ∼300 ms and 600 ms, respectively.

The first total synthesis of an arcutine-type C20-diterpenoid alkaloid arcutinine has been achieved in both racemic and asymmetric forms. Construction of the C4 quaternary center and the pyrrolidine E ring in an early stage proved to be important for achieving the successful synthesis of the target alkaloid. Strategically, an asymmetric conjugate addition/aldol cascade and a decarboxylative allylation reaction allowed the establishment of the vicinal all-carbon quaternary stereocenters at C4 and C5. Furthermore, a sequence consisting of an intramolecular aza-Wacker cyclization, an oxidative dearomatization/intramolecular Diels-Alder cycloaddition cascade, and a ketyl-olefin cyclization enabled the assembly of the core structure and led to the total synthesis of arcutinine.

Quinones are components of electron transport chains in photosynthesis and respiration. Acetylacetone (AA), structurally similar to benzoquinone (BQ) for the presence of two identical carbonyl groups, has been reported as a quinone-like electron shuttle. Both BQ and AA are important chemicals in the aquatic environment. However, little information is known about their interactions if co-existed. We found here that AA significantly enhanced the conversion of BQ. By analyzing the evolution of chemical concentration, solution pH, dissolved oxygen, and the final products, the interactions between AA and BQ were elucidated. The reactions between BQ and AA generated oxygen but ultimately led to the reduction of solution pH and dissolved oxygen. The reactions proceeded faster under indoor lighting condition than in the dark. The formation of semiquinone radicals is believed as the primary step. The secondary AA-derived radicals might be strongly oxidative or reductive, depending on the concentration of dissolved oxygen. Insoluble humus was generated in the mixture of BQ and AA. These results suggest that the presence of AA might interfere with photosynthesis and respiration through the interactions with quinones.

Ice slurry displays many advantages as a phase-change material for its high energy density and flowability. In typical mechanical scraping method, the strong interaction of ice with solid surface causes the problem of high energy consumption and damage of scrapers. Ice slurry generation process will be efficient if the ice adhesion strength could be reduced. In this paper, urea was proposed as an additive to depress ice adhesion in solutions. Ice particles was scoured easily by liquid flow and ice slurry was generated spontaneously. The thermal transition property, solidification morphology and adhesion characteristic of urea aqueous solutions were investigated respectively. Results show that the latent heat of urea solution was higher than other candidate solutions. Micro liquid film was observed at the solidification–substrate interface when the solution was in solid-liquid two-phase state. This phenomenon explains the lower adhesion strength of ice in aqueous solutions.

Anaerobic ammonium oxidation coupled to iron reduction, termed Feammox, is a new microbial process linked the nitrogen cycles. However, the nitrogen losses through Feammox from different ecosystem habitats remain unclear. In this study, isotope tracing technology and molecular microbial analysis were used to investigate the Feammox and its contribution to the nitrogen loss in the farmland and riparian soils, and river sediments. The potential Feammox rates were detected, which varied from 0.07 to 0.15 mg N kg−1 d−1 among the three ecosystem habitats. Feammox rates were significantly higher in the farmlands or riparian soils than in the river sediments. Feammox, denitrification and anaerobic ammonium oxidation (anammox) were estimated to account for approximately 3.5–4.2%, 92.6–93.1% and 2.8–3.9% of the total nitrogen losses respectively, while a significant correlation was observed between the Feammox rates and the denitrification rates (r = 0.72, P

The topsoil of sandy slope suffers from serious erosion due to its weak internal cohesion. Most of the efforts have been made to improve the stability of topsoil by recovering the inter-particle cohesion without due concern to environmental and ecological aspects. Thus, water-based polyurethane (PU) soil stabilizer is introduced to reinforce the topsoil of sandy slope for erosion control purpose. This study aims at understanding its reinforcement effect and proving the feasibility of polyurethane treatment in practice. A series of laboratory tests were performed on treated specimens with different PU concentrations and also compared to a fallow one by which the effect of this stabilizer on soil mechanical and hydrological properties, vegetation growth and erosion resistance were investigated. The results indicated that PU treatment can significantly increase the shear strength, unconfined compressive and tensile strength of natural sand. An increasing amount of PU resulted in marked improvements in cohesion, but slight changes in internal friction angle. On the other hand, the presence of PU conferred low permeability and good water stability to the natural sand. Even with a relatively small amount of PU treatment, a positive potential is observed in promoting the anti-erodibility of topsoil by enhancing its inter-particle cohesion due to the unique network membrane structure. Moreover, PU treatment also improved soil water retention characteristics and can provide a suitable environment for vegetation growth. Under the synergistic action of vegetation and polymer treatment, stronger erosion resistance of topsoil was observed. Thus, PU treatment can be used as an ecological and effective alternative method with regard to topsoil stabilization on sandy slope.

Polypyrrole (PPy) composite coatings have been effectively synthesized in the presence of TiO2 and V-TiO2 nanoparticles on carbon steel by electrochemical method in aqueous oxalic acid solutions. These coatings were characterized by different surface analysis methods. TEM results confirmed that the size of V-TiO2 nanoparticles (11.91 ± 1.03 nm) was smaller than that of TiO2 nanoparticles (17.22 ± 2.84 nm), therefore increasing the interaction between PPy composite coatings and metal surface. The electrical conductivity measurement was carried out to examine the electrical properties of TiO2/PPy and V-TiO2/PPy composite coatings. Besides, the electrochemical behaviors of these coatings were also studied in 0.1 M HCl solution by electrochemical impedance spectroscopy and potentiodynamic polarization measurements. Results showed that the V-TiO2/PPy composite coatings exhibited better anti-corrosion performance than TiO2/PPy composite coatings. The exceptional anti-corrosion performance of PPy composite coatings was associated with the synergistic effect of the increase in physical barrier, prevention of charge transport by TiO2 nanoparticles and the complex passive film on the metal surface.

As an extremely important post-transcriptional regulator, miRNAs are involved in a variety of crucial biological processes, and the abnormal expressions of miRNAs are closely related to a variety of diseases. In this work, for the first time, we designed a nucleic acid lock nanostructure for specific detection of miRNA-21, which changes the self-structure to "active conformation" by binding the target, in order to generate triggers to initiate the subsequent reaction. Emphatically, this flexible nucleic acid lock is capable of self-cleaving without the assistance of external component, overcoming the disadvantages of the complex design and requiring protease assistance in traditional nanostructure. Moreover, the combination of DNAzyme and RCA technology not only greatly improves the efficiency of signal amplification but also enables primer generation to simultaneous cascade RCA amplification. Additionally, the electrochemical detection technology based on silver nanoclusters overcomes the shortcomings of traditional detection methods such as low sensitivity and complex operation. The detection limit achieved was 9.3 aM with a wide dynamic response ranging from 10 aM to 100 pM (at the DPV peak of - 0.5 V), which is comparable to most of the reported studies. Therefore, our work provided an ultra-sensitive way for the detection of miRNAs using nanostructures and revealed an effective means for disease theranostics and cancer diagnosis. In this work, for the first time, we designed a nucleic acid lock nanostructure based on its self-structural transformation for the specific detection of miRNA. And the combination of DNAzyme and cascade RCA reaction greatly improved the signal amplification efficiency.

The accident happened on cable termination often starts from partial discharge which will cause electrical aging of insulating silicone oil. Therefore, the research on the electrical aging characteristics and products of the insulating silicone oil under partial discharge is significant. In this paper, a dielectric barrier discharge with pin plate electrodes is used to simulate partial discharges under real conditions. The electrical characteristics of the silicone oil and the products formed before and after the discharge are analyzed. It is found that prolonged partial discharges will significantly alter the dielectric properties of insulating silicone oils. The dielectric loss factor and the relative permittivity will increase and the volume resistivity will be greatly reduced. At the same time, gel-like substances polymerized by Si–O bonds and gases such as hydrogen and carbon monoxide were produced. Finally, changes at the molecular level were analyzed on the basis of the products and their formation and electrical aging properties were explained. In addition, the gas product characteristics were analyzed using the three-ratio method.

Strength and toughness are both of great importance for the application of polylactic acid (PLA). Unfortunately, these two properties are often contradictory. In this work, an effective and practical strategy is proposed by using carboxylated graphene oxide (GC) grafted with polyethylene glycol (PEG), i.e. GC-g-PEG. The synthesis procedure of GC-g-PEG is firstly optimized. Then, a series of PLA nanocomposites were prepared by the melt blending method via masterbatch. In comparison to that achieved over pure PLA, these nanocomposites are of higher crystallinity, thermal stability and mechanical strength. This is mainly attributed to well-tailored interface and good dispersion. Especially, while retaining the tensile strength of the original PLA, the elongation at break increases by seven times by adding 0.3 wt% GC-g-PEG.

The dynamic balance between bone formation and bone resorption is vital for the retention of bone mass. The abnormal activation of osteoclasts, unique cells that degrade the bone matrix, may result in many bone diseases such as osteoporosis. Osteoporosis, a bone metabolism disease, occurs when extreme osteoclast‐mediated bone resorption outstrips osteoblast‐related bone synthesis. Therefore, it is of great interest to identify agents that can regulate the activity of osteoclasts and prevent bone loss‐induced bone diseases. In this study, we found that N‐[2‐(4‐benzoyl‐1‐piperazinyl)phenyl]‐2‐(4‐chlorophenoxy) acetamide (PPOAC‐Bz) exerted a strong inhibitory effect on osteoclastogenesis. PPOAC‐Bz altered the mRNA expressions of several osteoclast‐specific marker genes and blocked the formation of mature osteoclasts, suppressing F‐actin belt formation and bone resorption activity in vitro. In addition, PPOAC‐Bz prevented OVX‐induced bone loss in vivo. These findings highlighted the potential of PPOAC‐Bz as a prospective drug for the treatment of osteolytic disorders.

Mn3O4 coated Ru nanoparticles (Ru@Mn3O4) were synthesized via a precipitation-reduction-gel method. The prepared catalysts were evaluated for partial hydrogenation of benzene towards cyclohexene generation by applying ZnSO4, MnSO4 and FeSO4 as reaction additives. The fresh and spent catalysts were thoroughly characterized by XRD, X ray fluorescence (XRF), XPS, TEM and N2-physicalsorption in order to understand the promotion effect of Mn3O4 as the modifier as well as ZnSO4, MnSO4 and FeSO4 as reaction additives. It was found that 72.0% of benzene conversion and 79.2% of cyclohexene selectivity was achieved after 25 min of reaction time over Ru@Mn3O4 with a molar ratio of Mn/Ru being 0.46. This can be rationalized in terms of the formed (Zn(OH)2)3(ZnSO4)(H2O)3 on the Ru surface from the reaction between Mn3O4 and the added ZnSO4. Furthermore, Fe2+ and Fe3+ compounds could be generated and adsorbed on the surface of Ru@Mn3O4 when FeSO4 is applied as a reaction additive. The most electrons were transferred from Ru to Fe, resulting in that lowest benzene conversion of 1.5% and the highest cyclohexene selectivity of 92.2% after 25 min of catalytic experiment. On the other hand, by utilizing MnSO4 as an additive, no electrons transfer was observed between Ru and Mn, which lead to the complete hydrogenation of benzene towards cyclohexane within 5 min. In comparison, moderate amount of electrons were transferred from Ru to Zn2+ in (Zn(OH)2)3(ZnSO4)(H2O)3 when ZnSO4 is used as a reaction additive, and the highest cyclohexene yield of 57.0% was obtained within 25 min of reaction time.

The efflux of anticancer agents mediated by P-glycoprotein (P-gp) is one of the main causes of multidrug resistance (MDR) and eventually leads to chemotherapy failure. To overcome this problem, the delivery of anticancer agents in combination with a P-gp inhibitor using nanocarrier systems is considered an effective strategy. On the basis of the physiological compatibility and excellent drug loading ability of erythrocytes, we hypothesized that nanoerythrocytes could be used for the codelivery of an anticancer agent and a P-gp inhibitor to overcome MDR in breast cancer. Herein, a folic acid-modified nanoerythrocyte system (PTX/TQR NPs@NanoRBC-PEG/FA) was prepared to simultaneously transport paclitaxel and tariquidar, and the in vitro and in vivo characteristics of this delivery system were evaluated through several experiments. The results indicated that the average diameter and surface potential of this nanocarrier system were 159.8 ± 1.4 nm and -10.98 mV, respectively. Within 120 h, sustained release of paclitaxel was observed in both pH 6.5 media and pH 7.4 media. Tariquidar release from this nanocarrier suppressed the P-gp function of MCF-7/Taxol cells and significantly increased the intracellular paclitaxel level (p < 0.01 versus the PTX group). The results of the MTT assay indicated that the simultaneous transportation of paclitaxel and tariquidar could significantly inhibit the growth of MCF-7 cells or MCF-7/Taxol cells. After 48 h of incubation with PTX/TQR NPs@NanoRBC-PEG/FA, the viability of MCF-7 cells and MCF-7/Taxol cells decreased to 7.37% and 30.2%, respectively, and the IC50 values were 2.49 μM and 6.30 μM. Pharmacokinetic results illustrated that, compared with free paclitaxel, all test paclitaxel nanoformulations prolonged the drug release time and showed similar plasma concentration-time profiles. The peak concentration (Cmax), area under the curve (AUC0-∞), and half-life (t1/2) of PTX/TQR NPs@NanoRBC-PEG/FA were 3.33 mg/L, 6.02 mg/L·h, and 5.84 h, respectively. Moreover, this active targeting nanocarrier dramatically increased the paclitaxel level in tumor tissues. Furthermore, compared with those of the other paclitaxel formulations, the cellular reactive oxygen species (ROS) and malondialdehyde (MDA) levels of the PTX/TQR NPs@NanoRBC-PEG/FA group increased by 1.38-fold (p < 0.01) and 1.36-fold (p < 0.01), respectively, and the activities of superoxide dismutase (SOD) and catalase (CAT) decreased to 67.8% (p < 0.01) and 65.4% (p < 0.001), respectively. More importantly, in vivo antitumor efficacy results proved that the PTX/TQR NPs@NanoRBC-PEG/FA group exerted an outstanding tumor inhibition effect with no marked body weight loss and fewer adverse effects. In conclusion, by utilizing the inherent and advantageous properties of erythrocytes and surface modification strategies, this biomimetic targeted drug delivery system provides a promising platform for the codelivery of an anticancer agent and a P-gp inhibitor to treat MDR in breast cancer.

Simultaneous removal of phosphorus (P) and algae is important to mitigate eutrophication, however, it is rather challenging in remediation of harmful algal blooms (HABs)-contaminated water. In this study, a wet alginate bead functionalized by CaO2 particle formed layer by layer was prepared with an in-situ method and optimized to remove phosphorous and inhibit algae growth. The stable H2O2 release with a concentration level of 0.06 mM was observed for a period of 26 d. The content of peroxy groups (-O-O-) in the optimal bead was 0.44 mmol·g−1 through permanganate-based titration study. For solution with an initial phosphorous concentration of 10 mg·L−1, the removal was around 97% in pH 3.0–10.0. XRD, SEM, and XPS studies and kinetic modelings showed that removal of phosphorus was mainly due to formation of insoluble Ca-P compounds in the bead. The CaO2-functionalized bead inhibited algae growth with an effect lasting over 170 d, which was much better than liquid H2O2 and Ca(OH)2 bead; the phosphorous removal with an efficiency of about 70% was simultaneously obtained. Furthermore, the bead demonstrated to be effective in removing algae in the realistic water from a reservoir. In summary, this study shows that the CaO2-functionalized material is promising for simultaneous removal of phosphorous and management of HABs.

Excessive phosphorus is one of the main reasons leading to eutrophication that causes severe ecosystem imbalance and negative human health impacts. In this study, several chitosan (CS)/lanthanum (La) hydrogel beads were first synthesized and tested for phosphorus removal. The stable cross-linked CS/La hydrogel bead prepared with the optimized conditions of 10 wt% La/CS and 1.5 mL of 5% glutaraldehyde demonstrated exceptional performance in the removal. It removed phosphate effectively from an aqueous solution in the pH range from 2 to 7. The complete phosphate uptake was achieved at contact time of 6 h under the completely mixing batch condition. The experimental maximum adsorption capacity of 107.7 mg g−1 was observed at solution pH 4. The phosphate adsorption was well described by the Freundlich isotherm and the intraparticle surface diffusion model. Furthermore, the adsorbent was effectively regenerated and reused in a five-cycle adsorption-desorption operation. The removal of phosphate can be attributed to electrostatic attraction and ion exchange. Moreover, the bead was capable of removing heavy metals: copper, zinc and lead. This adsorbent may be served as a cost-effective material for the treatment of phosphorus-contaminated water so as to minimize the occurrence of eutrophication.

Two ionic liquids with typical hydrophobic anions, 1-hydroxyethyl-3-2011methylimidazolium hexafluorophosphate ([(HOC2)MIm]PF6) and 1-hydroxyethyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide ([(HOC2)MIm]NTF2), were investigated as corrosion inhibitors for mild steel in 1.0 M HCl solution at 298 K. Electrochemical tests and scanning electron microscopy demonstrated that [(HOC2)MIm]PF6 exhibited better corrosion inhibition effect than that of [(HOC2)MIm]NTF2. Thermodynamic calculations and UV–visible spectroscopy analysis indicated that both of the inhibitors were adsorbed on the metal surface through physical interaction. The corrosion inhibition mechanisms were studied by molecular dynamic simulations. The [(HOC2)MIm]+ of [(HOC2)MIm]PF6 was adsorbed on the Fe surface in the water system and [PF6]− stayed above [(HOC2)MIm]+ while the adsorbed group of [(HOC2)MIm]NTF2 was [NTF2]−. The plane of [(HOC2)MIm]+ had a certain angle with the plane of [NTF2]− in the water bulk. [(HOC2)MIm]NTF2 owned greater spatial steric resistance, which contributed to its lower inhibition ability.

Polypyrrole (PPY) and polypyrrole-molybdate (PPY-MoO 4 2− ) coatings have been successfully electropolymerized on carbon steel by cyclic voltammetry method in aqueous oxalic acid solutions. These coatings were characterized by FTIR, XPS, EDX, FESEM and AFM methods. It was found that the incorporation of MoO 4 2− enhanced the corrosion resistance of PPY coating and improved the physical properties, such as thermostability, wettability, adhesion and hardness. The corrosion protection performance of PPY and PPY-MoO 4 2− coated steel in 0.1 M HCl solution was investigated by electrochemical impedance spectroscopy and Tafel polarization. Moreover, molecular dynamic simulations were engaged to assess the interactions between the metal surface and complex coatings. The exceptional anti-corrosion performance of PPY-MoO 4 2− coating was associated with the complex passive film on the metal surface and the barrier effect of the coating.

The ionic liquids, 1-vinyl-3-aminopropylimidazolium hexafluorophosphate ([VAIM][PF6]) and 1-vinyl-3-aminopropylimidazolium tetrafluoroborate ([VAIM][BF4]) acted as the corrosion inhibitors. Weight loss measurements showed the corrosion inhibition efficiencies of [VAIM][PF6] and [VAIM][BF4] were 90.53% and 54.01% at 45 °C, respectively. The ILs were mix-type inhibitors. Raising the temperature can have a decreased inhibition efficiency of [VAIM][BF4], while [VAIM][PF6] presented an opposite trend. In addition, [VAIM][PF6] obeyed Langmuir monolayer adsorption isotherm, while [VAIM][BF4] obeyed EI-Awady kinetic-thermodynamic adsorption for blocking active sites. Moreover, Molecular Dynamic Simulations showed that [VAIM][PF6] owned a higher adsorption energy, which may be responsible for the more adsorption groups of [VAIM][PF6].

The construction of stable, efficient and economical visible-light-driven photocatalyst is a practical strategy to deal with antibiotic water contamination. Herein, Cu3P nanoparticles/hollow tubular carbon nitride (HTCN) composite was successfully prepared and the photocatalytic activity of Cu3P/HTCN was evaluated with tetracycline (TC) as the degradation target antibiotic. Among them, the 6% Cu3P/HTCN exhibited optimal photocatalytic degradation rate (96.9% in 40 min), which was 8.3 times higher than that of pure HTCN. The enhancement of photocatalytic performance by Cu3P/HTCN is attributed to the introduction of Cu3P nanoparticles can not only increase the specific surface area of HTCN to provide abundant reaction sites, but also enhance the capture ability of incident light and promote the high-speed separation and transfer of photogenerated charges. In addition, the electron spin resonance (ESR) technology was used to further confirm that the main active species during the photocatalytic degradation of TC. Furthermore, the possible intermediates in photocatalytic degradation of TC by Cu3P/HTCN was the identified with liquid chromatography-mass spectrometry (LC-MS). This work provides an effective way for constructing HTCN-based composite materials for photocatalytic application.

Harmful algal bloom (HAB) is one of the most globally severe challenges in ecological system and water safety. Hydrogen peroxide has been commonly used in the management/treatment. Solid oxidants (e.g., peroxymonosulfate (PMS) and peroxydisulfate (PDS)) may outperform liquid H2O2 due to ease in transportation, handling, and applications. However, the information on applications of PMS and PDS in algae treatment is limited. In this study, the two solid peroxides and H2O2 were investigated for the removal of the blue-green algae of Microcystis aeruginosa. H2O2 and PMS effectively removed algae in 2 d at pH 5.0, 7.0 and 9.0, while PDS was only effective at pH 5.0. The change in pH and the release of dissolved organic carbon were insignificant at 0.2 mM H2O2 and PMS. The PMS could degrade microcystin-LR and phycobiliproteins. The studies of phycobiliproteins degradation and scanning electron microscopy indicated that PMS might cause the cell inactivation mainly by damaging the chemical components in algae cell wall and membrane while H2O2 might mainly enter the cell to form oxidation pressure to kill algae. The scavenger experiments showed that radicals were not crucial in H2O2 and PDS applications. Similarly, the algae removal by PMS was obtained mainly by non-radical pathways; about 77% was direct PMS oxidation and no more than 3% was singlet oxygen-mediated process, while radical pathways of sulfate radical and hydroxyl radical accounted for 18% and 2%, respectively. For the realistic algae-contaminated natural water, the PMS effectively lasted for 60 d, while the H2O2 lasted for 12 d. This research work demonstrates that the PMS is promising in control of HAB. The findings can provide some useful design and application parameters of PMS technology for better management/treatment of algae-contaminated water.

Arsenite contaminated water is one of severe global environmental problems. It is challenging to treat As(III) pollution by a one-step technology. In this study, we developed a Fe(III)/CaO2 Fenton-like technology for the treatment of As(III). The simultaneous oxidation of arsenite and removal of arsenic were achieved with efficiencies of nearly 100% and 95.8% respectively, which outperforms conventional technologies. It worked well in pH 3 to 9, and in the presence of cationic heavy metals, anions and humic acid. Moreover, the PO 4 3 − inhibited the removal of As(III). •OH and 1O2 played the important roles in the oxidation of As(III). The Ca(II) derived from CaO2 made a significant contribution to the oxidation and removal of As(III). The SEM and XPS studies confirmed that the formation of Ca-Fe nascent colloid caused the effective removal of arsenic. Our study demonstrates that the one-step Fe(III)/CaO2 technology has a great potential for purification of the As(III)-contaminated water.

The redox conversion of arsenite and nitrate has direct effects on their potential environment risks. Due to the similar reduction potentials, there are few technologies that can simultaneously oxidize arsenite and reduce nitrate in one process. Here, we demonstrate that a diketone-mediated photochemical process could efficiently do this. A combined experimental and theoretical investigation was conducted to elucidate the mechanisms behind the redox conversion in the UV/acetylacetone (AA) process. Our key finding is that UV irradiation significantly changed the redox potential of AA. The excited AA, 3(AA)*, acted as a semiquinone radical-like electron shuttle. For arsenite oxidation, the efficiency of 3(AA)* was 1-2 orders of magnitude higher than those of quinone-type electron shuttles, whereas the consumption of AA was 2-4 orders of magnitude less than those of benzonquinones. The oxidation of arsenite and reduction of nitrate could be both accelerated when they existed together in UV/AA process. The results indicate that small diketones are some neglected but potent electron shuttles of great application potential in regulating aquatic redox reactions with the combination of UV irradiation.

We have engineered an environmentally sustainable, biodegradable, and flame retardant poly (lactic acid) (PLA) based composite by introducing resorcinol bis (diphenyl phosphate) (RDP) coated cellulose fibers at a mass fraction of only 8%. Mechanical testing showed that formation of the composite significantly improved the impact strength, dynamic and elastic moduli, and tensile strength relative to neat PLA. The composite self-extinguished in less than 2 s and had greatly reduced dripping, hence easily passing the UL-94 V0 criteria. Fourier Transform Infrared Spectroscopy (FTIR) was used to elucidate the chemical mechanism responsible for these effects, which were interpreted in terms of a dehydration process of cellulose in the presence of RDP. This has an overall cooling effect and reduction of the combustion, which can be observed in the reduction of heat release rate (HRR) by cone calorimetry and increase in limiting oxygen index (LOI) value.

Surface passivation is a key limiting factor in the application of zero-valent iron (ZVI) for water remediation. Addition of ligands is a useful approach to overcome this issue. In this work, a small amount of acetylacetone (AA) (0.5 mM) was found highly efficient to enhance the reduction of nitrate by ZVI at near neutral conditions (pH 6.0) with the formation of considerable black coating on ZVI. At an initial nitrate concentration of 20 mg N/L, the pseudo first-order reduction rate constant of nitrate in the ZVI-AA-NO3- system was 0.0991 h-1, which was 52 times higher than that in the ZVI-NO3- system. Under otherwise identical conditions, the other five ligands, including EDTA, formate, acetate, oxalate, and phosphate, had negligible effects. Based on the pKa values of these ligands and the final species of iron, the ligand effects on nitrate reduction by ZVI were summarized from three aspects: (1) the ability to offer potentially dissociable protons from the ligands; (2) the complexation ability to eliminate iron (hydr)oxide precipitates from the surface of ZVI; and (3) the ability to lower down the redox potentials of iron species. The good performance of AA in these three aspects makes it advantage over the other ligands. A cycle test up to six runs demonstrates that AA could continuously take effect in the ZVI system. The results here point out the potential of AA as an effective ligand in ZVI system for enhanced contaminant transformation.

Quinones are important electron shuttles as well as micropollutants in the nature. Acetylacetone (AA) is a newly recognized electron shuttle in aqueous media exposed to UV irradiation. Herein, we studied the interactions between AA and hydroquinone (QH2) under steady-state and transient photochemical conditions to clarify the possible reactions and consequences if QH2 and AA coexist in a solution. Steady-state experimental results demonstrate that the interactions between AA and QH2 were strongly affected by dissolved oxygen. In O2-rich solutions, the phototransformation of QH2 was AA-independent. Both QH2 and AA utilize O2 as the electron acceptor, but in O2-insufficient solutions, AA became an important electron acceptor for the oxidation of QH2. In all cases, the coexistence of AA increased the phototransformation of QH2, whereas the decomposition of AA in O2-saturated and oversaturated solutions was inhibited by the presence of QH2. The underlying mechanisms were investigated by a combination of laser flash photolysis (LFP) and reduction potential analysis. The LFP results show that the excited AA serves as a better electron shuttle than QH2. As a consequence, AA might regulate the redox cycling of quinones, leading to significant effects on many processes, ranging from photosynthesis and respiration to photodegradation.

Cu(II)-EDTA is highly stable in a wide pH range (3.0∼12.0) and hard to be removed by the conventional precipitation method. Fe(III) displacement/UV photolysis/alkaline precipitation [Fe(III)/UV/NaOH] has been proposed as a promising method for the removal of Cu(II)-EDTA. Nevertheless, a high dose of Fe(III) is needed in this combined process, resulting in the production of a large amount of hazardous sludge. The photochemistry of Fe(III) is known to be ligand-dependent. Fe(III)-oxalate complexes are strongly photoactive. However, the addition of oxalic acid to the Fe(III)/UV/NaOH process was of little help. Acetylacetone (AA) is a good chelating ligand for many metals and has been proved as an efficient photo-activator. By introducing a low dose of AA ([AA]/[Cu] = 1.5) into the Fe(III)/UV/NaOH process, the Fe(III) dosage ([Fe]/[Cu]) was reduced from 10.4 to 3.2. As a result, the chemical cost was reduced from 13.9 to 7.6 kW h/m3. Meanwhile, the energy cost in the UV photolysis was reduced from 1066.5 to 752.4 kW h/m3. Most importantly, the sludge yields were reduced from 8.3 to 2.7 kg/m3 in a simulated wastewater and from 101.8 to 30.8 kg/m3 in a real electroplating wastewater. Such a sludge reduction is of great significance in mitigating the load of landfill.

Up to date, no great breakthrough has been made in the research of anaerobic ammonium oxidation mediated by Mn(IV)-oxide reduction (termed Mnammox). Recently, the Feammox process has become a hot research topic in the study of nitrogen loss from soils. Interestingly, in this study, an alternative pathway of N loss was proposed in terrestrial ecosystems. Mnammox could produce NO2−, NO3−, and N2 as end products. Here, our study demonstrated the occurrence of Mnammox, and direct evidence for Mnammox in agricultural drainage ditch soils with microbial Mn(IV) and Fe(III) reduction was obtained using the 15NH4+ isotopic tracing technique. The extent and rate of 30N2 and 29N2 production and Mn(IV) reduction were enhanced when amended with 15NH4+ and were further promoted when amended with 15NH4++MnO2. Moreover, although the Fe(III) reduction rate was stimulated with the addition of 15NH4+, the Fe(III) reduction rate greatly decreased when MnO2 was added. Mnammox rates ranged from 0.40 to 0.79 mg N kg−1 d−1, and an estimated 6.57–18.25 kg ha−1 year−1 N loss was associated with Mnammox in the examined soils. We revealed that the Mnammox reaction may be more efficient than the Feammox reaction, and the Feammox rates found in previous studies may have been overestimated. Overall, for the first time, this work provided key evidence for the existence of Mnammox in terrestrial ecosystems and suggested that Mnammox could be an important pathway for nitrogen loss in agricultural drainage ditch soils.

Research efforts on advanced oxidation processes (AOPs) have long been focused on the fundamental chemistry of activation processes and free radical reactions. Little attention has been paid to the chemistry of the precursor oxidants. Herein, we found that the precursor oxidants could lead to quite different outcomes. A counterintuitive result was observed in the photoreduction of bromate/iodate: the combination of H2O2 and UV enhanced the reduction of bromate/iodate, whereas the addition of persulfate to the UV system led to an inhibitory effect. Thermodynamic and kinetic evidence suggests that the reduction of bromate in UV/H2O2 was attributable to the direct reaction between HOBr and H2O2. Both experimental determination and kinetic simulation demonstrate that the reaction between HOBr and H2O2 dominated over the •OH-mediated reactions. These results suggest that H2O2 possesses some particular redox properties that distinguish it from other peroxides. The prototypical UV/H2O2 process is not always an AOP: it can also be an enhanced reduction process for chemicals with intermediates that are reducible by H2O2. Considering the increasing interest in persulfate-based AOPs, the results of this study identify some novel advantages of the classical H2O2-based AOPs.

Soil stabilizer can enhance the soil properties, which can improve ecological environmental problems such as soil erosion and slope instability. This study investigates the water-related and mechanical properties of soil stabilization using a polymer soil stabilizer solution synthesized from vinyl acetate polymer. The water properties test, mechanical properties test, durability test and seed growth test were carried out in the laboratory. Also, the effect of vinyl acetate polymer was verified by field tests. The results revealed that vinyl acetate polymer can enhance the water-retaining property, anti-erosion resistance, strength property and durability of soil, all of which increase with the increase of polymer concentration. At the same time, the polymer also has a certain promoting effect on vegetation growth. In addition, field tests proved that vinyl acetate polymer has good effects on soil engineering. These results could be applied as a reference for vinyl acetate polymer-improved soil engineering.

Silica has been regarded as one of the toughest contaminants in industrial water systems due to scaling. Several reports have shown that different generations of PAMAM are studied for silica scale inhibition efficiency and only the polyamidoamine PAMAM dendrimers with the core of ethylenediamine are discussed. However, hardly any data is available for PAMAMs with different reactive cores. In the light of this, the current work gets involved in the synthesis of amine-terminated dendrimers (PAMAM) of generation 0 G with reactive cores of different carbon chain lengths by divergent method employed to inhibit the growth of silica. The dendrimers of generation 0 G (PAMAM-0 G) with different carbon chain lengths (1,2-Ethylenediamine; 1,3-Diaminopropane; 1,4-Butanediamine and 1,6-Diaminohexane) as the core were synthesized by economical and green approach. The results showed that PAMAM-0 G-Prop was the most effective inhibitor, producing 415 mg/L molybdate reactive silica (83 % of the original quantity) at 40 mg/L after 24 h, an additional 295 mg/L as compared to the control. Also, PAMAMs profoundly affected the morphology of silica particles, resulting in a large quantity of small particles in solutions containing PAMAM-0 G-Prop or PAMAM-0 G-Eth, yet a small number of large ones in solutions containing PAMAM-0 G-But and PAMAM-0 G-Hex. By Molecular dynamics (MD) simulation, the results showed that the adsorption energy of PAMAM-0 G-Prop was greater than that of other PAMAM molecules. The order of adsorption energy of four dendrimers was PAMAM-0 G-Prop > PAMAM-0 G-But > PAMAM-0 G-Eth > PAMAM-0 G-Hex, and was certified by the analysis of correlation function. Finally, the simulation results provided theoretical basis for evaluating the properties of scale inhibitors and synthesizing novel efficient water treatment chemicals.

Hydrogenation of levulinic acid (LA) towards γ-valerolactone (GVL) is one of the most promising reactions in the field of biomass valorization to fine chemicals and liquid transportation fuels. Bimetallic Ni-Pt and Ni-Ru supported on ZrO 2 and γ-Al 2 O 3 were successfully utilized in this work as highly active and GVL-selective catalysts for the solvent-free hydrogenation of levulinic acid (LA) using formic acid (FA) as a hydrogen source in a microwave reactor, with results further translated into a continues flow system to prove the reaction mechanism. The supported bimetallic catalysts and their corresponding monometallic counterparts were characterized using N 2 -sorption, elemental analysis, X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS) and transmission electron microscopy (TEM). Under microwave irradiation, 100% selectivity to GVL was achieved using both mono- and bimetallic catalysts. Bimetallic Ni-Ru supported on γ-Al 2 O 3 shows the highest LA conversion (71%) among the studied catalysts. This high activity is attributed to a larger Ru° concentration on the surface of γ-Al 2 O 3 in comparison to ZrO 2 as well as to the textural properties of γ-Al 2 O 3 (i.e., surface acidity, specific surface area). In contrast, ZrO 2 ‐based catalysts exhibited a higher stability with respect to γ-Al 2 O 3 -based after four consecutive runs of reaction.

Simultaneous incorporation of palladium within Pd-Pd and/or Pd-Cu paddlewheels as framework-nodes and Pd nanoparticle (NP) dispersion into MOF have been achieved for the first time via one-pot synthesis. In particular, the framework substitution of Cu(2+) by Pd(2+) as well as the pore loading with PdNPs have been confirmed and characterized by XPS. The obtained solids featuring such multiple Pd-sites show enhanced catalytic activity in the aqueous-phase hydrogenation of p-nitrophenol (PNP) with NaBH4 to p-aminophenol (PAP).

Sand as a building material is pretty common in engineering constructions such as slopes and foundation pits. The great instability is generally generated because of the lack of cohesion inside and such instability is more serious during rains or when subjected to excessive external loads. This paper is aimed to study a combination of polyvinyl acetate polymer and sisal fiber as reinforcement materials. The focus of this study is to determine the effects of polymer content, fiber content, and dry sand density on the improvement in mechanical behavior of reinforced poorly graded sand. A series of direct shear, unconfined compression, and tensile tests on the reinforced sand have been conducted. The results suggest that the reinforcement effect increases with dry sand density up to 1.55 g/cm3 and then levels off. For fixed dry sand density, the strength of the improved sand enhances with the augment of polymer and plant fiber contents. At maximum contents, the reinforced sand can have 480 kPa of shear tensile strength, 1,276 kPa of unconfined compressive strength, and 240 kPa of tensile strength. The reinforcement mechanisms are revealed by Scanning Electron Microscope images. Polymer forms firm the polymer–soil matrices that enhance the fiber–sand interactions to mobilize tensile stresses. The combined use of polymer and fiber is preferred in engineering practices because of its zero negative impacts on the environment.

Graphitic carbon nitride (g-C3N4) has been regarded as an emerging and promising semiconductor photocatalyst for the solar hydrogen production and organic pollution removal. However, pure g-C3N4 typically exhibits moderate photocatalytic activity. And the amorphous structures and the rapid recombination of the electron-hole pairs are the two main challenges for the improved photocatalytic performance of the single bulk g-C3N4. In this work, we reported the CoP as a co-catalyst modified high-crystalline g-C3N4 (HCCN) to form an stable and highly efficient CoP/HCCN composite via a simple solvothermal method. As expected, the as-prepared composites showed impressive photocatalytic performance toward the tetracycline (TC) degradation. In particular, 5 wt% CoP/HCCN exhibited the optimum photocatalytic efficiency (96.7%, 120 min) and its corresponding degradation rate constant is 10.2 times than HCCN. Additionally, the role of coexisting ions in simulated practical TC wastewater was explored. The enhanced photocatalytic performance mainly derives from two factors: (i) the formation of HCCN to reduce structural defects; (ii) CoP as the cocatalyst on the HCCN surface to accelerate the separation of the photo-generated electrons-hole pairs and strengthen the surface photoreaction of the samples. Our work opens up a new window to the construction of highly effective HCCN-based composite photocatalysts for solar light-driven wastewater treatment.

TiO2 nanotubes with an average size of 6–9 nm were synthesized using a hydrothermal method and loaded with molybdate corrosion inhibitors. Then, the molybdate-loaded TiO2 nanotubes were incorporated into conducting polypyrrole (PPy) coatings using an electrochemical method for the corrosion protection of 304 stainless steel (304SS). The structure and morphology of the TiO2 and molybdate-loaded TiO2 nanotubes were characterized in details. UV–vis (UV–vis) results indicated that the loaded molybdate corrosion inhibitors in TiO2 nanotubes were slowly released in the natural environment. Scanning electron microscopy (SEM) images indicated the PPy/TiO2@Mo coating (5.59 ± 0.42 μm) was much thicker and smoother than PPy (2.27 ± 0.57 μm) and PPy/TiO2 (4.16 ± 0.51 μm) coatings. The corrosion behavior and electroactivity of PPy coatings with/without TiO2 nanotubes were evaluated using electrochemical methods in 3.5 % NaCl solution. Results confirmed the excellent anti-corrosion properties and electroactivity of the PPy/TiO2@Mo coating during 720 h of immersion. The notable improvement in the anti-corrosion performance of PPy/TiO2@Mo coating was attributed to the superior physical barrier, anodic protection and the loaded molybdate corrosion inhibitors being efficiently released from TiO2 nanotubes.

Generation of singlet oxygen (1O2) with metal-organic frameworks (MOFs) is limited by either poor light harvesting ability of type I MOFs or low availability of type II MOFs. Herein, we report a facile and widely applicable strategy, post-synthetic modification of type I MOFs with photo-redox active acetylacetone (AA) via a diazo coupling reaction, to enhance the visible-light-driven generation of 1O2 by MOFs. The introduction of AA to MOFs with variant metal nodes, such as Zr, Ti, Al, and Cr clusters, leads to intraligand charge transfer (ILCT), which not only strengthens the ligand to metal cluster charge transfer (LCCT) but also expands the photo-responsive edge of MOFs. Via the coupled ILCT and LCCT processes, UiO-66-AA functions as a hybrid type I-type II MOFs, which can efficiently generate 1O2 even at indoor lighting conditions. This work would open an avenue for the synthesis of MOFs towards diverse visible-light photocatalysis.