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Over the past several decades, major efforts have been directed toward the optimization of carrier concentrations to maximize thermoelectric performance. Chemical doping is an effective way to control carriers, but electrostatic gating provides a continuous tuning knob that enables effective and dynamic changes to the carrier density. Here, a method is reported that uses an electric‐double‐layer (EDL) transistor‐based ionic liquids gating to adjust the thermoelectric properties of thin films made from Nb‐doped SrTiO3 (Nb‐STO). This technique allows us to effectively change these properties at room temperature by varying the concentration of charge carriers within a broad range. A combination of lower film thickness and intrinsic carrier concentration leads to an enhanced ionic liquid‐gated response, resulting in an 18‐fold enhancement in power factor at room temperature for a 14 nm thin 4% Nb‐STO film at gate voltages within ±3.0 V. The present study offers new insights and strategies toward enhanced gate tunable thermoelectric properties in thin films. [ABSTRACT FROM AUTHOR]

Abstract: Enzyme immobilization is an established method for the enhancement of enzyme stability and reusability, two factors that are of great importance for industrial biocatalytic applications. Immobilization can be achieved by different methods and on a variety of carrier materials, both organic and inorganic. Inorganic materials provide the advantage of high stability and long service life which, together with the prolonged service life of the immobilized enzyme, can benefit the process economy. However, enzyme immobilization and increased stability often come at the cost of decreased enzyme activity. The main challenges involved in the design of an efficient immobilized enzyme system is to obtain both retention of high enzyme activity, enhanced stability and reusability, which is a complicated task, given the many variables involved, and the large numbers of methods and materials available. Simultaneously, new carrier materials and morphologies are constantly being developed. An investigation of enzyme immobilization systems on inorganic materials, with special emphasis on inorganic membranes, has been conducted in order to evaluate the effects of the immobilization system on the enzyme properties upon immobilization, i.e., activity, stability and reusability. The material properties of the enzyme carriers (particles and membranes) and their effects on the success of immobilization are described here. Furthermore, the reuse of inorganic membranes as enzyme carriers has been investigated and the reported examples show high ability of regeneration. To the best of our knowledge, this is the first review on enzyme immobilization focusing on the three fundamental aspects to consider when dealing with the topic: catalytic properties, enzyme leakage and reusability. Abbreviations: β‐Gal: β‐ d‐galactosidase; ADH: alcohol dehydrogenase; AFM: atomic force microscopy; APTES: 3‐aminopropyltriethoxysilane; APTMS: 3‐aminopropyltrimethoxysilane; BPA: bisphenol A; BSA: bovine serum albumin; CA: carbonic anhydrase; CALB: Candida antartica lipase B; CD: circular dichroism; CDI: carbonyldiimidazole; CLEA: cross‐linked enzyme aggregates; CLSM: confocal laser scanning microscopy; CNT: carbon nanotube; CPG: controlled pore glass; CRL: Candida rugosa lipase; DMeDMOS: dimethyldimethoxysilane; DRIFT: diffuse reflectance Fourier transform infrared; E2: 17β‐estradiol; EDC: N‐(3‐dimethylaminopropyl)‐N′‐ethylcarbodiimide hydrochloride; EDS: electron dispersive spectroscopy; FDH: formate dehydrogenase; FESEM: field emission scanning microscopy; FT‐IR: Fourier transform infrared spectroscopy; GA: glutaraldehyde; GCSZn: coal fly ashes glass‐ceramic zinc sulfate; GOD: glucose oxidase; GPS: 3‐(glycidyloxypropyl)trimethoxysilane; HDMI: hexamethylene diisocyanate; HRP: horseradish peroxidase; IEP: isoelectric point; IPTES: (3‐isocyanatopropyl)triethoxysilane; IR: infrared spectroscopy; LbL: layer‐by‐layer: MCP: metallic ceramic powder; MeTEOS: methyltriethoxysilane; MF: microfiltration; MML: Mucor miehei lipase; MNP: magnetic nanoparticle; MPTMS: 3‐mercaptopropyltrimethoxysilane; NHS: N‐hydroxysuccinimidyl; PAH: poly(allylamine hydrochloride); PEI: polyethyleneimine; PEG: polyethylene glycol; PES: polyether sulfone; PM‐IRRAS: polarization modulation infrared reflection absorption spectroscopy; pNPA: para‐nitrophenyl acetate; pNPP: para‐nitrophenyl palmitate; PSS: polystyrene sulfonate; PTMS: phenyltrimethoxysilane; ROL: Rhizopus oryzae lipase; SCAD: Saccharomyces cerevisiae alcohol dehydrogenase; SDS: sodium dodecyl sulfate; SDS‐2: sodium dodecyl sulfonate; SEM: scanning electron microscopy; TEM: transmission electron microscopy; TEOS: tetraethoxysilane; TGA: thermogravimetric analysis; TLL: Thermomyces lanuginosa lipase; TMP: transmembrane pressure; TTIP: titanium tetraisoproxide; TVL: Trametes versicolor laccase; UF: ultrafiltration; VTMS: vinyltrimethylsilane [ABSTRACT FROM AUTHOR]

The microstructural and compositional evolution during initial annealing of a superconducting (Bi,Pb)2Sr2Ca2Cu3O10+δ/Ag tape is studied using quantitative transmission electron microscopy. Special attention is devoted to the occurrence of Pb-rich liquids, which arc crucial for the Bi2Sr2CaCu2O8+&delta to (Bi,Pb)2Sr2Ca2Cu3O10+δ transformation, Ca and/or Pb-rich (Bi,Pb)2Sr2CaCu2O8+&delta grains dissolve into a liquid, which reacts with Ca-rich phases to increase the liquid's Ca-content. This leads to (Bi,Pb)2Sr2Ca2Cu3O10+δ formation. Apparently, a Ca/Sr ratio of around I is sufficient to keep (Bi,Pb)2Sr2Ca2Cu3O10+δ a nucleation going. It is confirmed that Ag particles are transported from the Ag-sheath into the oxide core by the liquid and not by mechanical treatment of the tape. [ABSTRACT FROM AUTHOR]

ZnO films prepared on glass plates using a water based coating solution are characterized and tested for methylene blue dye photocatalytic decolourization in various types of waters (demineralized water, sea‐, and lake‐water). The influence of various parameters such as wavelength and attenuation of incident radiation by dye and/or organic matter is studied. In demineralized water, up to 90% decoloration is achieved within 1 h with 365 nm irradiation on a 10 ml solution. Although the ZnO films still show some activity when illuminated by standard visible light lamps, the efficiency of the photocatalytic process is greatly reduced. Natural waters result in a significant decrease of the photocatalytic activity, under both UV and visible light irradiation. The main factor is believed to be enhanced UV light absorption within the liquid. The influence of organic and mineral matter in natural waters is briefly discussed. [ABSTRACT FROM AUTHOR]