The use of graphite/TiO2 nanocomposite additive for preparation of polyacrylic based visible-light induced antibacterial and self-cleaning coating

Research on Chemical Intermediates - Graphite/TiO2 nanocomposite additive was used to make a photocatalytic, hydrophilic, and antibacterial polyacrylic based coating. Various amounts of...     

Superhydrophobic and photocatalytic self-cleaning cotton fabric using flower-like N-doped TiO2/PDMS coating

Cellulose - Self-cleaning fabrics can be developed based on introducing two mechanisms of superhydrophobicity and photocatalytic activity to conventional fabrics. However, there are some downsides...     

In-situ preparation and electrochromic properties of TiO2/PTPA-HTAN core-shell nanocomposite film

A new star-shaped structure conjugated microporous polymers, poly (2,8,14-tri[4-diphenyl-benzene]-hexaazatrinaphthylene) (PTPA-HATN), was designed and in-situ electrochemically polymerized on the surfaces of FTO electrodes with a directional alignment TiO₂ nanorod array to obtain TiO₂/PTPA-HATN core-shell nanocomposite films. Compared with the PTPA-HATN film, the TiO₂/PTPA-HATN composite film exhibits higher optical contrast and faster response time, with contrast of 57% at 783 nm, coloring time of 3.62 s and discoloring time of 2.55 s (43%, 4.63 s and 4.77 s for PTPA-HATN film, respectively). After 400 cycles, the contrast of nanocomposite film decreased by 28%, while the PTPA-HATN film basically lost its electrochromic properties. A simple three-layer EC prototype device based on TiO₂/PTPA-HATN nanocomposite film constructed with hydrogel electrolyte clearly shows color changes at different voltages. On the one hand, the formation of core-shell porous nanostructure of TiO₂/PTPA-HATN composite film provides a larger ion doping/de-doping interface, shortening the average diffusion length of ions. On the other hand, the large indented polymer-nanorods contact interface makes it difficult for the polymer to detach from the electrode, thus significantly improving the cyclic stability of the composite film.     

Enhanced self-cleaning, antibacterial and UV protection properties of nano TiO2 treated textile through enzymatic pretreatment

Textile materials can be treated with some enzymes to improve their functionality. The usual enzymatic treatment hydrolyzes the textile surfaces that leads to increase the functional groups. Here, the polyester/wool fabric as a blend of fibers fabric was selected and treated with the two different types of enzymes to increase the surface activity with a propose of higher nano-TiO(2) adsorption. The fabric was first treated with proteases and lipases to hydrolyze the wool and the polyester surfaces, respectively. It has been then dipped into an ultrasound bath containing nano TiO(2) and cross-linking agent followed by curing. The cross-linking agent, butane tetracarboxylic acid (BTCA), also assisted to enhance the nano-particles adsorption and stabilization on the fabric surface. The self-cleaning properties of the fabrics were examined through evaluating the color removal from the stained fabric with Acid Blue 113. The antibacterial properties were determined by reduction growth of a Gram-negative bacteria E. coli. and the UV protection was assessed by UV-reflectance spectrum. The SEM pictures and EDX spectrums of some samples were also reported.     

Cu2O/Ag纳米复合材料的绿色制备与抗菌性能研究

以乙酸铜为铜源、硝酸银为银源并利用天然蜂蜜为还原剂在无模板剂无需高压反应釜的条件下,环保地、简便地制备了Cu_2O/Ag复合材料。并采用X射线衍射、扫描电镜对材料的结构与形貌进行了表征。通过抑菌圈法证明Cu_2O/Ag复合材料相比Cu_2O对大肠杆菌有着更好的抑菌性能,通过分析Cu_2O/Ag对大肠杆菌生长过程的影响发现,当Cu_2O/Ag复合材料的浓度达到10μg/m L时,Cu_2O/Ag复合材料能够彻底抑制大肠杆菌的生长。通过SEM观察了Cu_2O/Ag复合材料对大肠杆菌作用过程中菌种形貌的变化表明,Cu_2O/Ag复合材料对大肠杆菌的抗菌作用过程是先破坏细胞膜结构使细菌断裂成小段,这些小段颗粒逐渐皱缩进而彻底被分解为大分子物质。本文制备的Cu_2O/Ag复合材料在抗菌剂领域具有潜在的应用价值。     

Construction of multifunctional UV-resistant,antibacterial and photothermal cotton fabric via silver/melanin-like nanoparticles

Cellulose - As a kind of melanin-like nanoparticles, poly(levodopa) nanoparticles have abundant reactive catechol groups, which provide the basis for the structure design of melanin-like...     

Recyclable,superhydrophobic and effective Ag/TiO2@PDMS coated cotton fabric with visible-light photocatalyst for efficient water purification

Multifunctional materials for water purification have attracted significant attention due to the increased water pollution problems. However, fabricating the low-cost, effective, and recyclable separation material for wastewater containing various hazardous substances is still a challenge. Herein, we developed an Ag/TiO₂@PDMS coated cotton fabric with self-cleaning ability, high flux, superior visible-light photocatalytic ability, and recyclability via the “powder?+?glue” strategy. The composites are superhydrophobic (water contact angle 157°) and show high separation efficiency. After 20 times of repeated use, the separation efficiency remains 16,322 Lm^?2 h^?1, and methylene blue (MB) 's degradation rate remains almost unchanged. The high oil purification, catalytic property, excellent stability in harsh conditions, and recyclability enable the material as a satisfactory candidate for water purification.

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Low-temperature deposition and crystallization of RuO2/TiO2 on cotton fabric for efficient solar photocatalytic degradation of o-toluidine

A green low-temperature deposition and crystallization method was developed to uniformly coat RuO₂/TiO₂ nanocomposite onto cotton fabrics for efficient solar photocatalysis. The sequential growth of anatase TiO₂ and rutile RuO₂ on the surface of the cotton was confirmed by XRD, Raman and XPS characterizations. After the deposition of RuO₂, the optical properties of RuO₂/TiO₂/Cotton revealed better visible light absorption and higher charge mobility, and XPS spectra showed that the peaks of Ti 2p_3/2 and O 1 s shifted towards the lower binding energies due to the interfacial charge transfer at the robust RuO₂/TiO₂ mediated with Ti–O–Ru bonding. The photocatalytic performances of the RuO₂/TiO₂/Cotton were evaluated towards the photodegradation of o-toluidine (o-TD), an aromatic amine widely used in the chemical industry. Compared with TiO₂/Cotton, RuO₂/TiO₂/Cotton exhibited a remarkable improvement in the photocatalytic activity. The presence of RuO₂ on the surface of TiO₂/Cotton narrowed the band gap and improved the absorption of visible light. Moreover, the successful formation of a robust heterogeneous interface between TiO₂ and RuO₂ suppressed the charge carrier (e^–/h⁺) recombination effectively. With the RuO₂/TiO₂ coating chemically bound to the cotton fibers, RuO₂/TiO₂/Cotton delivered long-term stability in photocatalytic activity and high mechanical durability even after 20 washing times. Our facile and scalable synthesis strategy paved a universal route to efficient immobilization of visible-light-responsible TiO₂-based photocatalysts on the low-heat-resistant substrates for various applications.

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Green and facile microwave-assisted synthesis of TiO2/graphene nanocomposite and their photocatalytic activity for methylene blue degradation

TiO₂ (P25)/graphene nanocomposite photocatalyst have been successfully synthesized with P25 and different ratios of graphene oxide through a green and facile one-step microwave-assisted method. Graphene oxide was restored to graphene sheets and P25 was coated on it simultaneously during the reaction. The method offers easy access to the semiconductor/graphene nanocomposites with a uniform coating and strong interactions between semiconductor and the underlying graphene sheets. The prepared P25/graphene nanocrystals hybrid has superior photocatalytic activity in the degradation of methylene blue, showing an impressive photocatalytic enhancement over P25. The improved photocatalytic activities may be attributed to increased adsorptivity of dyes, extended light absorption range, and efficient charge separation properties of a two-dimensional graphene network.     

溶胶-凝胶法制备ZrO2/SiO2纳米复合材料的研究

利用溶胶-凝胶法制备了ZrO2/SiO2纳米复合物室温磷光材料,通过各条件的优化,最终确定溶剂为异丙醇、Zr摩尔掺杂百分含量为15%、550℃下煅烧3h得到的纳米ZrO2/SiO2复合物的室温磷光发光性能较好,其最大激发波长为280nm、发射波长为460nm,且磷光寿命为0.56s。     

Greener route for microwave enhanced syntheses of bioactive 1,5-benzodiazepines using heterogeneous calcium ferrite/graphene oxide nanocomposite as a novel and sustainable catalyst

In the present paper, a novel and benign protocol for microwave enhanced one pot syntheses of 2,3-dihydro-1,5 benzodiazepine derivatives from substituted acetophenones, aryl-aldehydes and o-phenylene diamine using heterogeneous calcium ferrite/graphene oxide (CF/GO) nanocomposite has been reported. The catalyst was prepared by ultrasonication method and characterized by spectral and analytical techniques. The CF/GO nanocomposite was employed for environmentally benign synthesis of 2,3-dihydro-1,5 benzodiazepines. The synthesized benzodiazepine derivatives were screened for their antimicrobial activities against various bacteria and fungi. The present synthetic strategy offered several advantages such as excellent yields in short span of time, simple modus operandi, ease of isolation and purification of products, simple recovery and reusability of the catalyst. A tentative mechanism for synthesis of 2,3-dihydro-1,5 benzodiazepine using CF/GO nanocatalyst has also been proposed.     

Study of Pt/TiO2 nanocomposite for cancer-cell treatment

The increasing incidence of cancer all over the world demands new, effective and secure materials for treatment. In this paper, we propose Pt/TiO₂ nanocomposite for cancer-cell treatment because noble metal nanoparticles are supposed to enhance the photocatalytic activity of TiO₂ nanoparticles. To evaluate the cancer-cell killing effect of our Pt/TiO₂ nanocomposite, TiO₂ and Au/TiO₂ nanoparticles are also introduced. The prepared Pt/TiO₂ nanocomposite are characterized with transmission electron microscopy (TEM) and UV–vis adsorption spectra. Results of cell treatment indicate that Pt/TiO₂ nanocomposite, as extremely stable metal–semiconductor nanomaterial, can exhibit a very high photodynamic efficiency under a mild ultraviolet radiation. And our Pt/TiO₂ nanocomposite shows to be more effective in cancer-cell treatment than TiO₂ and Au/TiO₂ nanoparticles. As a result, Pt/TiO₂ nanocomposite may be supposed to have a promising application for cancer-cell treatment.     

Ag/TiO_2/freeze-dried graphene nanocomposite as a high performance photocatalyst under visible light irradiation

Ag/TiO_2/freeze-dried graphene nanocomposites have been prepared via a facile one-step solvothermal method for the photocatalytic degradation of Rh B under visible light irradiation. During the solvothermal process, reduction of graphene oxide and loading of Ag/TiO_2 nanoparticles on graphene sheets were achieved. Investigation of chemical state of products showed that covering of Ag/TiO_2 surface with higher weight ratio of graphene resulting in that Ag metals in Ag/TiO_2 were oxidized to Ag2 O in nanocomposite structure after solvothermal process. Degree of photocatalytic activity enhancement strongly depends on the coverage of Ag/TiO_2 surface by porous graphene. The sample of 1 wt% porous graphene hybridized Ag/TiO_2 showed the highest photocatalytic activity, which is related to high migration efficiency of photoinduced of electrons and reduction of electron–hole recombination rate due to high electrical conductivity of graphene. Expanding of absorption to visible light region was ascribed to surface plasmon resonance effect of Ag metals and presence of graphene. Investigation of photocatalytic performance of formic acid as a dye-less organic pollutant showed that dye sensitization effect of Rh B molecules during evaluation of photocatalytic performance was negligible.     

Synthesis of layered double hydroxides/graphene oxide nanocomposite as a novel high-temperature CO_2 adsorbent

In this contribution, a novel high-temperature CO2 adsorbent consisting of Mg-Al layered double hydroxide(LDH) and graphene oxide(GO)nanosheets was prepared and evaluated. The nanocomposite-type adsorbent was synthesized based on the electrostatically driven self-assembly between positively charged Mg-Al LDH single sheet and negatively charged GO monolayer. The characteristics of this novel adsorbent were investigated using XRD, FE-SEM, HRTEM, FT-IR, BET and TGA. The results showed that both the CO2 adsorption capacity and the multicycle stability of LDH were increased with the addition of GO owing to the enhanced particle dispersion and stabilization. In particular, the absolute CO2 capture capacity of LDH was increased by more than twice by adding 6.54 wt% GO as support. GO appeared to be especially effective for supporting LDH sheets. Moreover, the CO2 capture capacity of the adsorbent could be further increased by doping with 15 wt%K2CO3. This work demonstrated a new approach for the preparation of LDH-based hybrid-type adsorbents for CO2 capture.     

Hydrothermal preparation and electrochemical sensing properties of TiO(2)-graphene nanocomposite

A facile hydrothermal method has been developed and shown to be effective for the preparation of TiO(2)-graphene nanocomposite. The as-prepared nanocomposite was characterized using FT-IR spectroscopy, powder X-ray diffraction (XRD) and scanning electron microscopy (SEM). The TiO(2)-graphene modified glassy carbon electrode (GCE) exhibited remarkable electron transfer kinetics and electrocatalytic activity toward the oxidation of dopamine (DA). Furthermore, the oxidation of common interfering agent such as ascorbic acid (AA) was significantly suppressed at this modified electrode, which resulted in good selectivity and sensitivity for electrochemical sensing of DA. These results demonstrate that the TiO(2)-graphene hybrid material has promising potential applications in electrochemical sensors and biosensors design.     

Electrochemical study on different layers of graphene based TiO2/graphene composites as an anode for lithium-ion batteries

Research on Chemical Intermediates - In order to explore the influence of the layers of graphene on the lithium-ion battery composites, to increase the electroconductivity of TiO2 and...     

Synthesis,complexation and antifungal,antibacterial activity studies of a new macrocyclic schiff base

A new macrocyclic ligand, L was synthesized using the high dilution condition with condensation of triethylene glycol diamine and terephtalaldehyde in ethanol. The obtained product, L was identified by FT‐IR, ¹H‐NMR, ¹³C‐NMR and Mass spectroscopy. The extraction equilibrium constants were estimated using dichloromethane/water membranes transfer with ICP‐AES and AES spectroscopy. Biological studies of this compound was determinated with disc diffusion method. The biological activity results showed that the synthesized ligand L has high activity against the studied microorganisms and high complexation ability against the Fe²⁺ cation.     

A gold-containing TiO complex: a crystalline molecular precursor as an alternative route to Au/TiO2 composites

The gold-containing titanium peroxo-complex AuCl4(NH4)7[Ti4(O2)4(Hcit)2(cit)2].12H2O 1 allows an easy reproducible access to pure Au/TiO2 composites.     

TiO2纳米晶复合纳米棒染料敏化太阳能电池

通过二次水热法合成锐钛矿TiO₂纳米棒(ANR). 采用X射线衍射(XRD)、场发射扫描电镜(FE-SEM)和透射电镜(TEM)等手段对其进行表征. 通过调节ANR和锐钛矿纳米颗粒(ANP)的掺杂比例来增加TiO₂纳米晶膜的光捕获效率和电子传输速率, 并对比了单层结构(ANR+ANP)和双层结构(ANP/(ANR+ANP))的纳米晶膜光阳极的光电转化性能. 在AM 1.5、光强100 mW·cm^-2的模拟太阳光下测试, 染料N719敏化的双层结构太阳能电池光电转化效率达7.3%, 比相同条件下单层纯ANP光阳极器件的光电转化效率(6.1%)提高了20%.     

Synthesis of layered double hydroxides/graphene oxide nanocomposite as a novel high-temperature CO2 adsorbent

In this contribution, a novel high-temperature CO2 adsorbent consisting of Mg-Al layered double hydroxide(LDH) and graphene oxide(GO)nanosheets was prepared and evaluated. The nanocomposite-type adsorbent was synthesized based on the electrostatically driven self-assembly between positively charged Mg-Al LDH single sheet and negatively charged GO monolayer. The characteristics of this novel adsorbent were investigated using XRD, FE-SEM, HRTEM, FT-IR, BET and TGA. The results showed that both the CO2 adsorption capacity and the multicycle stability of LDH were increased with the addition of GO owing to the enhanced particle dispersion and stabilization. In particular, the absolute CO2 capture capacity of LDH was increased by more than twice by adding 6.54 wt% GO as support. GO appeared to be especially effective for supporting LDH sheets. Moreover, the CO2 capture capacity of the adsorbent could be further increased by doping with 15 wt%K2CO3. This work demonstrated a new approach for the preparation of LDH-based hybrid-type adsorbents for CO2 capture.