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The increase of reaction temperature of electrocatalysts and the construction of heterogeneous structures is regarded as an efficient method to improve the electrocatalytic water splitting activity. Here, we report an approach to enhance the local heat and active sites of the catalyst by building a heterostructure with Co9S8 to significantly improve its electrocatalytic performance. The as-fabricated Co9S8@Ce-NiCo LDH/NF electrode possesses a notable photothermal ability, as it effectively converts near-infrared (NIR) light into the local heat, owing to its significant optical absorption. Leveraging these favorable qualities, the prepared Co9S8@Ce-NiCo LDH/NF electrode showed impressive performance in both hydrogen evolution reaction (HER) (η100 = 144 mV) and oxygen evolution reaction (OER) (η100 = 229 mV) under NIR light. Compared to the absence of the NIR light, the presence of NIR irradiation leads to a 24.6 % increase in catalytic efficiency for HER and a 15.8 % increase for OER. Additionally, other dual-functional electrocatalysts like NiCo-P, NiFeMo, and NiFe(OH)x also demonstrated significantly enhanced photothermal effects and improved catalytic performance owing to the augmented photothermal conversion when combined with Co9S8. This work offers novel pathways for the development of photothermal-electrocatalytic systems that facilitate economically efficient and energy-conserving overall water splitting processes.
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At present, in the field of geotechnical engineering and agricultural production, with increasingly serious pollution an environmentally friendly and efficient means is urgently needed to improve the soil mass. This paper mainly studied the microbial induced calcium carbonate precipitation (MICP) technology and the combined effect of MICP technology and lignin on the improvement of silt in the Beijing area. Through unconfined compressive strength and dynamic triaxial test methods, samples improved by microorganisms were studied to obtain the optimal values of cement concentration and lignin under these two test schemes. The results show that after the incubation time of Sporosarcina pasteurii reached 24 h, the OD600 value was 1.7-2.0 and the activity value (U) was 930-1000 mM ms/min. In the unconfined static pressure strength test, after MICP treatment the optimal concentration of cementitious solution for constant temperature and humidity samples and constant-temperature immersion samples was 1.25 mol/L. The compressive strength of the constant temperature and humidity sample was 1.73 MPa, and the compressive strength of the constant-temperature immersion sample was 3.62 Mpa. At the concentration of 1.25 mol/L of cement solution, MICP technology combined with lignin could improve the constant temperature and humidity silt sample. The optimal addition ratio of lignin was 4%, and its compressive strength was 1.9 MPa. The optimal lignin addition ratio of the sample soaked at a constant temperature was 3%, and the compressive strength was 4.84 MPa. In the dynamic triaxial multi-stage cyclic load test, the optimal concentration of cementation solution for the constant temperature and humidity sample after MICP treatment was 1.0 mol/L, and the failure was mainly inclined cracks. However, in the condition of joint improvement of MICP and lignin, the sample mainly had a drum-shaped deformation, the optimal lignin addition ratio was 4%, and the maximum axial load that the sample could bear was 306.08 N. When the axial dynamic load reached 300 N, the strain accumulation of the 4% group was only 2.3 mm. In this paper, lignin, an ecofriendly material, was introduced on the basis of MICP technology. According to the failure shape and relevant results of the sample, the addition of lignin was beneficial for the improvement of the compressive strength of the sample.
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In practical engineering applications, silt is prone to liquefaction and quicksand. This paper mainly studies the improvement effects of urease, lignin and their mixture on the strength and liquefaction resistance of silt. Based on the results and phenomena of an unconfined compressive strength and dynamic triaxial test, the improvement effects of the compressive strength, deformation resistance and liquefaction resistance of silt under different improvement schemes are analyzed, and the optimal values of the cement or lignin when enzyme-induced calcium carbonate precipitation (EICP) technology, lignin alone or EICP and lignin are obtained. The results show that the optimum concentration of the constant temperature and humidity sample (referred to as the constant humidity sample) and the constant temperature immersion sample (referred to as the soaking sample) of urease in the unconfined compressive strength test is 1.0 mol/L, and the compressive strength of the soaking sample is 4.9 MPa, which is 1.56 times that of the constant humidity sample; the optimum addition ratio of the lignin-improved constant humidity sample is 3%, and its compressive strength is 2.07 Mpa; the optimum addition ratio of the samples immersed at constant temperature is 4%, and the compressive strength is 3.05 MPa; when urease combines with lignin to improve silt, 4% is the best lignin addition ratio, the compressive strength of the constant humidity sample reaches 1.57 Mpa and the compressive strength of the soaking sample reaches 3.75 MPa; in the dynamic triaxial multi-stage cyclic load test, all samples were cured at constant humidity sample, and in the urease modified silt scheme, 1.0 mol/L was the optimal cement concentration; in the scheme of improving silt with lignin, 3% is the optimal addition ratio; when 1.25 mol/L cementation solution plus urease crude extract is combined with different ratios of lignin in the experimental scheme, 3% is the best lignin addition ratio.
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The introduction of oxygen vacancies (Ov) into photoanodes has been considered an effective method to enhance the photoelectrochemical (PEC) water splitting performance. The efficiency of water splitting is related to light absorption, charge separation to the electrode surface, and charge injection into the electrolyte. However, introducing Ov from a single level cannot meet the above objectives. In this work, we present the fabrication of BiVO4 (BVO) photoanodes with bulk and surface Ov, and their respective roles in the PEC performance have been studied. The bulk OV of the photoanode could increase the carrier density and improve the separation efficiency of photogenerated electrons and holes. The surface Ov provide abundant surface active sites, and enhance the charge injection efficiency. Charge separation efficiency of the nitrogen-treated BVO (N:BVO) (69.1 % at 0.75 V vs RHE and 85.1 % at 1.23 V vs RHE) has a noticeable increase compared with that of BVO (51.2 % at 0.75 V vs RHE and 64.6 % at 1.23 V vs RHE), nevertheless, only a minor enhancement of charge injection efficiency (from 49.1 % to 56.5 % at 1.23 V vs RHE). After the deposition of NiFeOOH, the photoanodes present superior charges injection efficiency in the whole range of applied potential. The as-synthesized N:BVO/U-NiFeOOH photoanode exhibits a photocurrent density of 5.52 mA·cm-2 at 1.23 V vs RHE with a 97 % Faradaic efficiency for O2/H2 evolution. Thus, there is a synergistic effect between the bulk OV and surface OV on the BVO photoanode, exhibiting highly promoted PEC water splitting activity relative to the individual OV decorated BVO for oxygen evolution reaction, which provides a promising strategy for fabricating efficient solar water splitting systems.
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In this paper, we focus on the application of mechanical properties in a soil-rock mixture modified by microbial mineralization under the influence of different factors, including pH value, cementing solution concentration, and cementing time. Cementing fluids and samples with different pH values, calcium ion concentrations, and mineralization cementation were prepared. The process of urea hydrolysis MICP under different factors was studied. A solidified soil-rock mixture sample under triaxial compression was measured. Then, combined with scanning test methods, such as SEM and XRD, the influence of different factors on the mechanical strength and failure mode of the soil-rock mixture structure was analyzed from a microscopic point of view. The results show that a low concentration of cementing solution with a high concentration of bacteria liquid generated the highest calcium carbonate content and the strongest cementing ability. When the pH value of the cementation solution is six, the cementation effect between the pores is the best, and the deviatoric stress is stronger. When wet-curing samples, short or long curing time will adversely affect the strength of soil-rock mixture samples, the strongest curing and cementing ability is 5 days. The microscopic results show that the microbial mineralization technology fills the pores between the particles, and the interaction force between particles is enhanced to enhance the strength of the soil-rock mixture.
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BACKGROUND This study aimed to investigate the effectiveness of perioperative parecoxib sodium combined with transversus abdominis plane (TAP) block on postoperative pain management following hepatectomy in patients with hepatocellular carcinoma (HCC). MATERIAL AND METHODS One hundred patients with HCC who underwent hepatectomy were randomized into a study group (n=51) and a control group (n=49). The study group received 40 mg of parecoxib sodium 30 minutes before anesthetic induction, and 150 mg of 0.375% ropivacaine with 5 mg dexamethasone as TAP inhibitors, before closing the abdominal incision. The control group received 40 mg of placebo 30 minutes before anesthetic induction, without TAP block. Postoperatively, all patients received patient-controlled intravenous analgesia (PCIA) and evaluation with subjective visual analog scale (VAS) pain scores. Data on adverse events, postoperative ambulation (>6 hours/day), time of flatus and defecation, and hospitalization duration were recorded. RESULTS Pain scores of the study group were significantly lower compared with the control group on the first three postoperative days. No significant differences were found between the two groups in terms of adverse events. In the study group, the number of cases of postoperative ambulation was significantly more than the control group. The onset of flatus and defecation and duration of hospital stay in the study group were significantly shorter in the study group compared with the control group. CONCLUSIONS Parecoxib sodium combined with TAP block effectively reduced postoperative pain, improved ambulation, improved gastrointestinal function, and shortened hospitalization time following hepatectomy in patients with HCC without adverse effects.
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Isoxazoles/farmacología , Manejo del Dolor/métodos , Dolor Postoperatorio/tratamiento farmacológico , Músculos Abdominales/efectos de los fármacos , Adulto , Anciano , Analgesia Controlada por el Paciente/métodos , Analgésicos Opioides/administración & dosificación , Anestésicos Locales/administración & dosificación , Carcinoma Hepatocelular/tratamiento farmacológico , Carcinoma Hepatocelular/cirugía , China , Femenino , Hepatectomía , Humanos , Neoplasias Hepáticas/tratamiento farmacológico , Neoplasias Hepáticas/cirugía , Masculino , Persona de Mediana Edad , Bloqueo Nervioso/métodos , Dimensión del Dolor/métodos , Complicaciones Posoperatorias/tratamiento farmacológico , Estudios Prospectivos , Ropivacaína/farmacologíaRESUMEN
Petroleum refinery wastewater (PRW) treatments based on biofilm membrane bioreactor (BF-MBR) technology is an ideal approach and biofilm supporting material is a critical factor. In this study, BF-MBR with nano-attapulgite clay compounded hydrophilic urethane foams (AT/HUFs) as a biofilm support was used to treat PRW with a hydraulic retention time of 5â¯h. The removal rate of 500â¯mg/L chemical oxygen demand (COD), 15â¯mg/L NH4+ and 180 NTU of turbidity were 99.73%, 97.48% and 99.99%, which were 23%, 20%, and 6% higher than in the control bioreactor, respectively. These results were comparatively higher than that observed for the sequencing batch reactor (SBR). The death rate of the Spirodela polyrrhiza (L.) irrigated with BF-MBR-treated water was 4.44%, which was similar to that of the plants irrigated with tap water (3.33%) and SBR-treated water (5.56%), but significantly lower than that irrigated with raw water (84.44%). The counts demonstrated by qPCR for total bacteria, denitrifiers, nitrite oxidizing bacteria, ammonia oxidizing bacteria, and ammonia-oxidizing archaea were also higher in BF-MBR than those obtained by SBR. Moreover, the results of 16â¯s rRNA sequencing have demonstrated that the wastewater remediation microbes were enriched in AT/HUFs, e.g., Acidovorax can degrade polycyclic aromatic hydrocarbons, and Sulfuritalea is an efficient nitrite degrader. In summary, BF-MBR using AT/HUF as a biofilm support improves microbiome of the actived sludge and is reliable for oil-refinery wastewater treatment.
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Reactores Biológicos/microbiología , Compuestos de Magnesio/química , Compuestos de Silicona/química , Uretano/química , Eliminación de Residuos Líquidos/métodos , Aguas Residuales/química , Biopelículas/crecimiento & desarrollo , Arcilla/química , Membranas Artificiales , Aguas Residuales/microbiología , Purificación del AguaRESUMEN
A molybdenum disulfide (MoS2) nanosheet-decorated titanium dioxide (TiO2) NRA heterojunction composite was fabricated successfully through a two-step hydrothermal approach. Microstructures and optical properties of specimens were characterized by field-emission scanning electron microscopy, X-ray diffractometry, X-ray photoelectron spectroscopy, and ultraviolet-visible spectroscopy. The gaps of the TiO2 nanorods have been filled with tiny MoS2 nanosheets, which can increase the surface area of MoS2/TiO2 NRA composite thin films. In addition, the photocatalytic activity of the thin films were measured and discussed in greater detail. The appropriate hydrothermal reaction temperature of MoS2 is important for the growth of perfect MoS2/TiO2 NRA composites with significantly enhanced photocatalytic performance. The photodegradation rate and k value of MoS2-220/TiO2 are 86% and 0.0105 min-1, respectively, which are much larger than those of blank TiO2. The enhanced photocatalytic performance could be attributed to the higher visible light absorption and the reduced recombination rate of photogenerated electron-hole pairs.
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Solution based deposition has been recently considered as a viable option for low-cost flexible electronics. In this context, research efforts have been increasingly focused on the development of suitable solution-processed materials for oxide based transistors. In this work, we report a fully solution synthesis route, using 2-methoxyethanol as solvent, for the preparation of In2O3 thin films and ZrO x gate dielectrics, as well as the fabrication of In2O3-based TFTs. To verify the possible applications of ZrO x thin films as the gate dielectric in complementary metal oxide semiconductor (CMOS) electronics, fully solution-induced In2O3 TFTs based on ZrO2 dielectrics have been integrated and investigated. The devices, with an optimized annealing temperature of 300 °C, have demonstrated high electrical performance and operational stability at a low voltage of 2 V, including a high µ sat of 4.42 cm2 V-1 s-1, low threshold voltage of 0.31 V, threshold voltage shift of 0.15 V under positive bias stress for 7200 s, and large I on/I off of 7.5 × 107, respectively. The as-fabricated In2O3/ZrO x TFTs enable fully solution-derived oxide TFTs for potential application in portable and low-power consumption electronics.
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Nanoporous anatase TiO2 films were fabricated by a screen-printing method, and CuxO quantum dots (QDs) were deposited on the TiO2 films through successive ionic layer adsorption and reaction (SILAR). The amount of CuxO QDs on the TiO2 films are controlled by changing the number of SILAR cycles. The morphology, microstructure, optical, and photoelectrochemical properties of different CuxO sensitized TiO2 films (CuxO/TiO2) were investigated in detail. The nanoporous TiO2 film offers a large surface area for anchoring QDs. QD deposited samples exhibited a significant improvement in photoelectrochemical performance than the bare of TiO2. CuxO/TiO2, prepared with 7 SILAR cycles, showed the best photoelectrochemical properties, where the photocurrent density was enhanced to 500.01 µA/cm2 compared with 168.88 µA/cm2 of bare TiO2 under visible light. These results indicate that the designed CuxO/TiO2 structure possesses superior charge separation efficiency and photoelectrochemical properties.
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Apoptosis of osteoblasts triggered by high-dose glucocorticoids (GCs) has been identified as a major cause of osteoporosis. However, the molecular mechanisms underlying GC-induced osteoporosis remain elusive. This study was conducted to make clear the mechanism of GC-induced osteoblast apoptosis and to examine whether reduction of ER stress by 4-PBA inhibited osteoblast apoptosis. After treatment with dexamethasone (Dex) or hydrocortisone, cell viability was assessed using an MTT assay. Flow cytometry was performed to assess the apoptosis of MC3T3-E1 cells. The expression levels of ER stress-related proteins (CHOP, GRP78, eIF2α, and phospho-eIF2α) and apoptosis-related proteins (cleaved Caspase-3, Bcl-2, and Bax) in MC3T3-E1 cells were measured by Western blot analysis. We found that both Dex and hydrocortisone reduced cell proliferation and promoted apoptosis in MC3T3-E1 cells. In addition, the protein expression levels of cleaved Caspase-3 and Bax increased and the protein expression level of Bcl-2 decreased in MC3T3-E1 cells exposed to Dex. In addition, the Dex exposure also resulted in a release of cytochrome c (Cyt C) from mitochondria. The cellular ATP content was decreased following prolonged treatment with Dex. 4-PBA attenuated ER stress and mitochondrial dysfunction induced by Dex in MC3T3-E1 cells. Dex-mediated apoptosis of MC3T3-E1 cells is aggravated by ER stress. Moreover, Dex-induced apoptosis in MC3T3-E1 cells was inhibited by 4-PBA, suggesting that ER stress involved in Dex-induced apoptosis. In conclusion, inhibition of ER stress by 4-PBA could reduce GC-induced apoptosis in MC3T3-E1 cells.
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Apoptosis/efectos de los fármacos , Estrés del Retículo Endoplásmico/efectos de los fármacos , Glucocorticoides/efectos adversos , Osteoblastos/patología , Fenilbutiratos/farmacología , Animales , Butilaminas/farmacología , Caspasa 3/metabolismo , Línea Celular , Dexametasona/efectos adversos , Chaperón BiP del Retículo Endoplásmico , Humanos , Ratones , Mitocondrias/efectos de los fármacos , Mitocondrias/metabolismo , Osteoblastos/efectos de los fármacos , Osteoblastos/metabolismo , Tapsigargina/farmacologíaRESUMEN
Inorganic nitrogen and heavy metals pervasively co-exist in industrial and domestic wastewaters. In this work, Pseudomonas brassicacearum LZ-4 was tested for the simultaneous reduction of Cr(VI) and nitrate. Nitrate was found to be the best inorganic nitrogen source for strain LZ-4, and could promote Cr(VI) reduction. Cr(VI) had a low degree of inhibition on denitrification, and even 50mgL-1 Cr(VI) did not inhibit reduction of 100mgL-1 NO3--N. The capability of simultaneous reduction of Cr(VI) and nitrate was illustrated by the reductase genes contained in the LZ-4 genome. Application in a batch membrane bioreactor showed that the immobilized strain LZ-4 could remove over 95% of 500mgL-1 NO3--N, 80% of 10mgL-1 Cr(VI), and 96% of 5000mgL-1 COD in each batch of 46days. In summary, the strain LZ-4 is an ideal candidate for remediation of co-contaminants.
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Reactores Biológicos , Cromo/química , Pseudomonas , Aguas Residuales/química , Purificación del Agua/métodos , Desnitrificación , Metales Pesados , Nitratos/química , Nitrógeno/química , Aguas Residuales/microbiologíaRESUMEN
BACKGROUND: Osteoarthritis (OA) is a complex arthritic condition in which the genetic factor plays a crucial role. A single nucleotide polymorphism (SNP), rs1137101 (Gln223Arg) of leptin receptor (LEPR) gene has been demonstrated to be associated with susceptibility to knee OA. However, this association in Chinese Han population has never been examined. The present study aimed to investigate whether Gln223Arg was related to knee OA susceptibility in a Northwest Chinese population with Han ethnicity. METHODS: Gln223Arg polymorphisms were genotyped in 587 patients with confirmed knee OA and in 628 age- and sex-matched healthy controls using polymerase chain reaction-restriction fragment length polymorphism analysis. Besides, LEPR genotypes were verified by direct DNA sequencing analysis on PCR products. RESULTS: The genotype and allele frequencies in LEPR SNP rs1137101 were significantly different between cases and control groups (chi-square = 6.52, P = 0.038 for genotype and chi-square = 5.06, P = 0.024 for allele frequencies; respectively). Rs1137101 was correlated with knee OA in the dominant genetic model (GG + GA versus AA) (P = 0.016) and a higher G allele frequency existed (P = 0.024) among all patients with knee OA and controls. On stratification analysis, the genotype GG and G allele were associated with susceptibility to knee OA in females, both young (≤65 years) and old groups (>65 years) and patients with mild knee OA. CONCLUSIONS: Our finding suggested that the genetic variant of LEPR gene rs1137101 is independently related to knee OA susceptibility in Northwest Chinese population with Han ethnicity and may serve as a potential biomarker to determine risk of knee OA.
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Pueblo Asiatico/genética , Predisposición Genética a la Enfermedad , Osteoartritis de la Rodilla/genética , Polimorfismo de Nucleótido Simple/genética , Receptores de Leptina/genética , Anciano , Análisis del Polimorfismo de Longitud de Fragmentos Amplificados , Arginina/genética , Biomarcadores , Estudios de Casos y Controles , Etnicidad/genética , Femenino , Frecuencia de los Genes , Genotipo , Glutamina/genética , Humanos , Masculino , Persona de Mediana Edad , Análisis de Secuencia de ADN , Factores SexualesRESUMEN
Receptor activator of nuclear factor-κB ligand (RANKL) is a key factor in the differentiation and activation of osteoclasts. Echinocystic acid (EA), a pentacyclic triterpene isolated from the fruits of Gleditsia sinensis Lam, was reported to prevent reduction of bone mass and strength and improve the cancellous bone structure and biochemical properties in ovariectomy rats. However, the molecular mechanism of EA on the osteoclast formation has not been reported. The purpose of this study was to investigate the effects and mechanism of EA on RANKL-induced osteoclastogenesis. Our results showed that EA inhibited the formation of osteoclast, as well as the expression of osteoclastogenesis-related marker proteins in bone marrow macrophages (BMMs). At molecular levels, EA inhibited RANKL-induced NF-κB activation and ERK phosphorylation in BMMs. In conclusion, the present study demonstrated that EA can suppress osteoclastogenesis in vitro. Moreover, we clarified that these inhibitory effects of EA occur through suppression of NF-κB and ERK activation. Therefore, EA may be a potential agent in the treatment of osteoclast-related diseases such as osteoporosis.
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Sistema de Señalización de MAP Quinasas/fisiología , FN-kappa B/metabolismo , Ácido Oleanólico/análogos & derivados , Osteoclastos/citología , Osteoclastos/fisiología , Osteogénesis/fisiología , Animales , Células de la Médula Ósea/citología , Células de la Médula Ósea/efectos de los fármacos , Células de la Médula Ósea/fisiología , Diferenciación Celular/efectos de los fármacos , Diferenciación Celular/fisiología , Células Cultivadas , Relación Dosis-Respuesta a Droga , Regulación de la Expresión Génica/efectos de los fármacos , Regulación de la Expresión Génica/fisiología , Sistema de Señalización de MAP Quinasas/efectos de los fármacos , Ratones , Ratones Endogámicos C57BL , Ácido Oleanólico/administración & dosificación , Osteoclastos/efectos de los fármacos , Osteogénesis/efectos de los fármacosRESUMEN
Acupuncture has been shown to lessen the inflammatory reaction after acute spinal cord injury and reduce secondary injury. However, the mechanism of action remains unclear. In this study, a rat model of spinal cord injury was established by compressing the T8-9 segments using a modified Nystrom method. Twenty-four hours after injury, Zusanli (ST36), Xuanzhong (GB39), Futu (ST32) and Sanyinjiao (SP6) were stimulated with electroacupuncture. Rats with spinal cord injury alone were used as controls. At 2, 4 and 6 weeks after injury, acetylcholinesterase (AChE) activity at the site of injury, the number of medium and large neurons in the spinal cord anterior horn, glial cell line-derived neurotrophic factor (GDNF) mRNA expression, and Basso, Beattie and Bresnahan locomotor rating scale scores were greater in the electroacupuncture group compared with the control group. These results demonstrate that electroacupuncture increases AChE activity, up-regulates GDNF mRNA expression, and promotes the recovery of motor neuron function in the anterior horn after spinal cord injury.
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Highly ordered TiO2 nanotube arrays (TiO2-NTAs), with a uniform tube size on titanium substrate, were obtained by means of reoxidation and annealing. A composite structure, CdSe quantum dots@TiO2 nanotube arrays (CdSe QDs@TiO2-NTAs), was fabricated by assembling CdSe quantum dots into TiO2-NTAs via cyclic voltammetry electrochemical deposition. The X-ray diffractometer (XRD), field-emission scanning electron microscope (SEM), and transmission electron microscope (TEM) were carried out for the determination of the composition and structure of the tubular layers. Optical properties were investigated by ultraviolet-visible spectrophotometer (UV-Vis). Photocurrent response under visible light illumination and photocatalytic activity of samples by degradation of methyl orange were measured. The results demonstrated that the photo absorption of the composite film shifted to the visible region, and the photocurrent intensity was greatly enhanced due to the assembly of CdSe QDs. Especially, photocurrent achieved a maximum of 1.853 µA/cm(2) after five voltammetry cycles of all samples. After irradiation under ultra violet-visible light for 2 h, the degradation rate of composition to methyl orange (MO) reached 88.20%, demonstrating that the CdSe QDs@TiO2-NTAs exhibited higher photocatalytic activity.
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Highly ordered TiO2 nanotube array (TN) films were prepared by anodization of titanium foil in a mixed electrolyte solution of glycerin and NH4F and then annealed at 200°C, 400°C, 600°C, and 800°C, respectively. The samples were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), water contact angle (WCA), and photoluminescence (PL). It was found that low temperature (below 600°C) has no significant influence on surface morphology, but the diameter of the nanotube increases from 40 to 50 nm with increasing temperature. At 800°C, the nanotube arrays are completely destroyed and only dense rutile film is observed. Samples unannealed and annealed at 200°C are amorphous. At 400°C, anatase phase appears. At 600°C, rutile phase appears. At 800°C, anatase phase changes into rutile phase completely. The wettability of the TN films shows that the WCAs for all samples freshly annealed at different temperatures are about 0°. After the annealed samples have been stored in air for 1 month, the WCAs increase to 130°, 133°, 135°, 141°, and 77°, respectively. Upon ultraviolet (UV) irradiation, they exhibit a significant transition from hydrophobicity to hydrophilicity. Especially, samples unannealed and annealed at 400°C show high photoinduced hydrophilicity.
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ZnO thin films have been synthesized by means of a simple hydrothermal method with different solvents. The effect of deionized water content in the mixed solvents on the surface morphology, crystal structure, and optical property has been investigated by scanning electron microscopy, X-ray diffraction, and UV-Vis spectrophotometer. A large number of compact and well-aligned hexagonal ZnO nanorods and the maximal texture coefficient have been observed in the thin film, which is grown in the mixed solvent with x = 40%. A lot of sparse, diagonal, and pointed nanorods can be seen in the ZnO thin film, which is grown in the 40-mL DI water solution. The optical band gap decreases firstly and then increases with the increase of x. Reversible wettability of ZnO thin films were studied by home-made water contact angle apparatus. Reversible transition between hydrophobicity and hydrophilicity may be attributed to the change of surface chemical composition, surface roughness and the proportion of nonpolar planes on the surface of ZnO thin films. Photocurrent response of ZnO thin films grown at different solvents were measured in air. The response duration of the thin film, which is grown in the solvent with x = 40%, exhibits a fast growth in the beginning but cannot approach the saturate current value within 100 s. The theoretical mechanism for the slower growth or decay duration of the photocurrent has been discussed in detail.