Many kinds of rare and precious metals such as Au, Ag and Pt are generated as by-products in the treatment process of copper anode slime, which makes the downstream applications and new products of these noble metals an important way to achieve high-value utilization. In this paper, we used AgNO3 and Na2S¡¤9H2O as precursor solutions to synthesize Ag2S quantum dots (QDs) onto the transparent polyaniline counter electrodes (PANI CEs) by successive ionic layer adsorption and reaction (SILAR) method. The composite film of PANI/Ag2S showed an improved light absorption at 200-800 nm, indicating the higher light harvesting efficiency of the bifacial quasi-solid-state dye-sensitized solar cells (DSSCs). And the cyclic voltammograms and Tafel plots indicated that the PANI/Ag2S film exhibited an enhanced electrocatalytic activity for I3- reduction. The IMPS/VS results showed that the PANI/Ag2S CE based DSSC possesses enhanced electron transfer process. Thus, the bifacial DSSC fabricated with PANI/Ag2S CE showed an improved power conversion efficiency up to 6.25% under both front and rear sides illumination, which was higher than that of DSSC assembled with pure PANI CE (5.57%).

Electrolysis of solid oxides in molten chlorides were well documented as a greener and more affordable preparation of silicon and/or germanium powders which are building blocks not only for traditional metallurgical industries and also for high-tech areas including solar cells, batteries, chips and etc. Deep and thorough insights into the reaction mechanisms and structural characteristics of the electrolytic samples are the prerequisites on optimizing the process and fully exploiting the functionalities of electrolytic samples. Herein, the existence of liquid process during electrolysis of solid SiO2 and GeO2 in molten chlorides was verified. The implications of the forenamed liquid process on the energy efficiency, chemical compositions and microstructures of the electrolytic products were also discussed. Reaction mechanisms on the controllable preparation of Si and/or Ge with different nanostructures including nanoparticle, one-dimensional nanostructure, porous nanostructure and hollow nanostructure were also highlighted.

This paper is focus on nucleation and metastability with the objective of defining ranges of optimal supersaturation with respect to product quality. For batch reactive crystallization, a new definition of critical metastable zone width (CMSZW) was proposed. The induction time for batch reactive crystallization of calcium carbonate from unseeded aqueous supersaturated CaCl2¨C(NH4)2CO3 system were measured at different supersaturation ratios under 10 oC using focused beam reflectance measurement (FBRM). The determination of critical metastable zone width depended on the induction time. The induction time data was analyzed to calculate interfacial energy and various nucleation parameters, such as the radius of critical nucleus (rc), the critical free energy of nucleus (∆Gcrit), etc. Experimental results demonstrated that homogeneous nucleation predominated at high supersaturation and the heterogeneous nucleation prevailed at low supersaturation. It was recommended to maintain an optimum supersaturation everywhere and all the time in the crystallizer with respect to the mean crystal size and the purity of the crystals and when the concentration of initial CaCl2 solution, ranged from 0.1 mol/L to 0.5 mol/L, was 0.4 mol/L, the rc and ∆Gcrit achieved the maximum value.

In this presentation, our recent progress on the development of nickel (oxy)hydroxide/graphene (NiOOH or Ni(OH)2) hydrogels, with mesoporous NiOOH or flower-like Ni(OH)2 nanosheets uniformly dispersed within the highly interconnected 3D graphene network, were constructed by a mixed solvothermal and hydrothermal reaction. The effect of solvent composition on the morphology, phase, and dispersibility of nanocrystal and hydrogel strength were systematically studied. As binder-free electrodes of supercapacitors, these two hydrogels both deliver high capacitance with excellent rate capability. The charge-storage mechanisms are in-depth investigated by quantifying the kinetics of charge storage, which reveals that nickel (oxy)hydroxide exhibits both capacitive effects and diffusion-controlled battery-type behavior during charge storage. During the study, pure graphene hydrogels are also prepared and used as negative electrodes, which show an impressive specific capacitance. Benefitting from the synergistic contribution of both positive and negative electrodes, the assembled asymmetric supercapacitors achieve a remarkable energy density of 66.8 Wh/kg at a power density of 800 W/kg, and excellent cycling stability with 85.3% capacitance retention after 8000 cycles, holding great promise for energy storage applications.

Two small molecule donor materials (DTGe(FBTTh2) 2 and DTGe(FBTBFu) 2) incorporating the dithienogermole (DTGe) moiety with fluorobenzothiadiazole (FBT) and bithiophene (Th2) or benzofuran (BFu) end-capping groups are synthesized and their properties as donor materials in small molecule bulk heterojunction type (BHJ) solar cells are investigated. The DTGe(FBTTh2) 2 with Th2 end groups shows outstanding solar cell characteristics with efficiencies up to 6.4% using a standard BHJ architecture and 7.3% using a ZnO optical spacer, while the BFu end-capped DTGe(FBTBFu)2 has slightly wider band gaps and yields slightly higher open circuit voltage ( VOC ) at the expense of short circuit current ( JSC ) and fill factor (FF). In this study, the DTGe-based molecules are systematically compared to the dithienosilole(DTSi)-based analogues, which are currently among the highest power conversion efficiency (PCE) small molecule solar cell donor materials known. The JSC produced by the DTGe molecule is found to be similar to, or slightly higher than the Si analogue, despite similar absorption characteristics, however, the PCE is similar to the Si analogues due to small decreases in VOC and FF. This report marks the first small molecule BHJ based on a Ge-containing heterocycle with PCE over 7%.

Generating energy, as a key factor for the development of the country, implies a number of factors that requires solving its rational use in the context of sustainable economic, social, environmental and cultural issues. The aim of our research described in this paper is to investigate and evaluate several aspects of energy efficiency, such as source and use of energy and its loss in education buildings, when it comes to lighting and heating of the building during the learning process; as well as medium-term strategies for alternative energy sources for these items. The key issue in this study is based on analysis and assessment of enclosed architectural space and its constructive elements, electrical and heating installations of the case study building, the Faculty of Electrical and Computer Engineering, Faculty of Civil Engineering and Architecture and Faculty of Mechanical Engineering, so-called Technical Faculties Building (TFB). This paper is based on comparing the analysis from different viewpoints and energy indicators of the standard audit process in certain buildings in Kosovo. Methods and tools used in this study are a standard audit, initiated by acquaintances of existing state - identification of energy consumption and energy efficiency measures. On the basis of the needs and capacity utilization of energy supply in TFB; and in relevant local and international experiences, this paper attends to contribute in addressing the efficient energy use, in suggesting improvements of constructive elements and alternative energy sources, in particular, discusses the general awareness of the university authorities in Kosovo, in relation to energy efficiency and economic benefits of improved technical-engineering conditions of educational buildings.

Whether a particular education system is of high or low quality can be judged in terms of input, output and process. Until recently, however, much discussion of educational quality is centered on only system inputs in terms of the provision of teachers, teaching materials and other facilities, and on output in terms of students’ achievement. However, due to financial constraints, the government has realized that improving the quality of education through improved input is more difficult.

Carbon Nanotubes and graphene have exceptional properties such as stiffness, strength, thermal and electrical conductivity. However, the integration of carbon nanotubes and graphene requires their development beyond conventional composites so that the level of the non-nano material is designed to integrate fully with the amount of nanotubes and graphene. Here the nano microstructural constituents are part of the matrix rather than a differing component, as in the case of conventional composites. In order to advance the integration of nano materials such as carbon nanotubes and graphene, this research is focused on the simultaneous control of the nano-architecture, structural properties, thermal and electrical conductivity of fully integrated materials. These are often hybrid materials systems designed to surpass the limits of the rule of mixtures in nano engineering and composite design. The goals are to implement multifunctional designs to fully mimic the properties of carbon nanotubes and grapheme on larger scales for enhanced thermal and electrical management in addition to the control of other properties such as strength, toughness energy and power. These new approaches involve exfoliation, functionalization, dispersion, stabilization, alignment, polymerization, reaction bonding and coating in order to achieve full integration. Typical examples of integration in liquid, polymer and ceramic matrices and applications in energy systems are presented and discussed.

Considering that a high compatibility at hybrid organic/inorganic interfaces can be achieved using polar and hydrophilic functionalities, this approach is used to improve inverted polymer solar cell performance by introducing nonionic phosphonate side chains (at 0%, 5%, 15%, and 30% substitution levels) into a series of isoindigo-based polymers (PIIGDT-Pn). This approach led to ¡O20% improvement in power conversion efficiency compared to a nonmodified control polymer, via an increased short-circuit current (J SC). This enhancement is believed to stem from reduced nongerminate recombination and improved charge carried extraction when the level of phosphonate substitution is optimized. These results are substantiated by a combination of detailed electrical measurements including space-charged limited current modeling, light intensity¨Cdependent photocurrent (J ph) analysis, and morphological studies (grazing-incidence wide-angle X-ray scattering and atomic force microscopy). This is the first practical report demonstrating the use of nonionic polar side chains to control charge carrier dynamics in an existing photovoltaic polymer structure. It is envisioned that this simple strategy may be applied to other material systems and yield new materials with the potential for even higher performance.

Reliable analytical measurements of environmental samples are essential ingredients of sound decisions involving many facets of society including safeguarding the public health, improving the quality of environment and facilitating advances in technology. Neutron activation analysis (NAA) and Isotope dilution analysis (IDA) are among the most revolutionary techniques which strode past to other analytical methods. NAA is an extremely sensitive, selective and precise method which yields wealth of information on major, minor and trace constituents of just few milligram samples of all kind of matrices. An advantage of NAA its abilities to simultaneously determined most elements in the Periodic table with low detection limit.
NAA and IDA has been widely used for geological, biological, environmental, industrial, archaeological and forensic samples. These have been used as standard techniques for the characterization of Standard/ Certified Reference materials at the National Institute of Standard and Technology (NIST, USA), International Atomic Energy Agency (IAEA), Vienna and other such agencies. Basic principle of NAA is to irradiate the material with neutrons resulting in the production of Radioactive nuclide with the emission of β- and ϒ-radiations. The elemental concentration were calculated using the respective gamma ray energies.
In the present paper we have employed NAA and IDA for the multi-elemental (~40 elements up-to ppm and ppb level) analysis of large number of natural systems such as water, soil, fugitive and ambient dust particulates matter from industrial establishments and several other samples of environmental importance using 113 cm-3 HPGe detector (PGT, Germany). Also several Environmental Standard/ Certified Reference Materials were analysed for quality assurance of our data as well as a part of Inter-laboratory comparison study. An attempt has been made to attribute the elemental contents to possible sources of origin.
(Key words: Nuclear, Environment, NAA, IDA)

The great success that lithium-ion batteries (LIBs) have experienced in portable electronic devices is now being extended to electric vehicles (EVs), which require both high power density and high energy density. Despite the large theoretical capacity of 372 mAh g¨C1, the commonly used graphite anode material suffers from its poor rate performance and safety. Among the recently developed anode materials, Li4Ti5O12 probably has received the most attention. Although Li4Ti5O12 can be modified to be a superior anode material with high rate performance, good cyclability and high safety, its main problem of the intrinsically small theoretical capacity (175 mAh g¨C1) cannot be solved. Due to the Nb5+/Nb3+ redox couple, niobium-based oxides have large theoretical capacities, which are comparable with that of graphite. However, some of these oxides suffer from the low (electronic and ionic) conductivities. In this study, a few niobium-based oxides are fabricated; then some of them are modified through crystal-structure modification, compositing, nanosizing and their combined methods. Consequently, several niobium-based oxides, with the same advantages of Li4Ti5O12 but much larger capacities, can fulfil the requirements of both high power density and high energy density, thus may find its promising applications in the LIBs of EVs.

Low grade phosphorus-containing iron ore (LGPIO), a raw and wasted industrial solid material was used as an adsorbent to remove Cu(II) cation from wastewater. The effects of initial pH value, adsorptive time, initial Cu(II) cation concentration, adsorptive temperature and LGPIO dosage on the Cu(II) cation removal efficiency were studied. The results show that the Cu(II) cation removal efficiencies exceed 99.65% and Cu(II) cation concentrations are less than 0.30 mg/L under the conditions of pH value 6.1, temperature 25oC, adsorptive time 30 min, initial Cu(II) cation concentration 100 mg/L, particle size lower than 0.147 mm, adsorbent dosage 10 g/L and stirring speed 250 r/min. After Cu(II) cation removal reaction, the Cu(II) cation concentrations completely accord with the requirement of national discharge standard of water pollutants for iron and steel industry (GB 13456-2012) (TCu(II)=0.5 mg/L) in China. Therefore, it can be concluded that LGPIO is a new low-cost adsorbent which is suitable for the adsorption of Cu(II) cation from wastewater.

It is the key technology of coke oven gas utilization to get rid of the influence of the impurities of coke oven gas. The thermodynamic laws of reforming of coke oven gas were studied by thermodynamic calculation in this paper. The factors like temperature¡¢system pressure¡¢iron monoxide and water which impact the change law of self-reforming of coke oven gas was researched via the heat balance equation and material balance. The results show that higher temperature, lower system pressure and an appropriate reducing atmosphere is working for coke oven gas auto-reforming. The coke oven gas auto-reforming accomplished when the temperature increased to 1173K and the system pressure was 2 atm. Carbon separation has happened when the methane content increased to 28% or lower iron monoxide content. The concentration of water had no effect on coke oven gas auto-reforming.

As the world population is increasing continuously, the energy demand is becoming a major challenge for the world’s energy sector. At present, energy supply mainly depends on fossil fuels which are directly related to environmental pollution. Moreover, the nuclear disaster in Fukushima, Japan in 2011 has diverted world’s attention to alternative fuel resources. Under this situation, substitutes for conventional fuel sources are in major trust areas in current research and technology. One of the alternatives to fossil fuels is solid oxide fuel cells (SOFCs). SOFCs have attracted wide attention due to its high efficiency, fuel flexibility and minimum carbon emission.
SOFCs are the class of fuel cells that are mainly based on solid oxide electrolyte. The most extensive electrolyte used for SOFC is YSZ, although high operating temperature nearly 800C is required to achieve sufficient oxide-ion conductivity. The high operating temperature of these cells lead to many problems related to material stability and compatibility with other components of SOFCs and also thermal degradation of the electrolyte itself. Therefore, now considerable attention is given in developing solid electrolytes which can operate at the intermediate temperature range (600-800C). Na-doped SrSiO3 has been investigated for its use as a solid electrolyte.
Sr1-xNaxSiO3-d (x=0.0, 0.10, 0.20, 0.30 and 0.40) have been synthesized by simple solid state reaction method. The X-ray diffraction study indicated the formation of monoclinic phase. Raman analysis is performed to support the XRD results. AC impedance spectroscopy is used to study the conductivity of the system. Sr0.6Na0.4SiO3-d showed the highest conductivity of 22.8 mS/cm at 800 C in air. The SEM analysis indicated that secondary phase is co-formed, which is segregated along the grain-boundary regions. DSC analysis further supported the formation of the amorphous phase.

This paper presents the technological process of solidification for the treatment of hazardous waste in Petrochemical plant. The treatment is based on the technological process of physical and chemical reactions of waste mixtures with additives on the basis of calcium and obtaining a reaction product as a solid inert powder (solidificate). The technological process is carried out in terms of exothermic molecular encapsulation.

Noble metal free electrocatalysts with a large effective active area and good long-term stability for hydrogen evolution reaction (HER) are of critical importance for sustainable hydrogen production from water electrolysis. In this work, 3D porous NiMo films were electrodeposited under super gravity field. The surface structure evolution of NiMo films dependent on electrodeposition time was studied. The catalytic activities and stability of the NiMo films for HER were investigated. It was found that an induction period for porous structure formation existed under super gravity field. During electrodeposition, compact NiMo film with dispersed protuberances was firstly generated. Then, porous NiMo films were obtained with the increase of electrodeposition time due to the rapid growth of protuberances. The compact-porous graded NiMo films were prepared. However, compact NiMo film was only electrodeposited under normal gravity condition. The porous NiMo film with large surface roughness exhibited high catalytic activity and good long-term stability for HER in alkaline solution.

Lithium-ion batteries (LIBs) are promising energy storage devices for portable electronics, electric vehicles, and power-grid applications. It is desirable to develop a simple and scalable method for constructions of sustainable materials for safe LIBs with high rate performance. Titania has superior safety and better rate performance than graphite, the state-of-the-art anode material for LIBs; however, its electrochemical performance is still hindered by the sluggish Li-ion diffusion and poor electronic conductivity. Herein, we present the synthesis of hydrogen titanate ultrathin nanobelts via a wet-chemistry route at ambient conditions. With the morphology remained stable, the hydrogen titanate can be easily converted to anatase TiO2 by a subsequent calcination. The resultant anatase nanobelts show excellent performances when utilized as an anode for LIBs. Moreover, this synthetic strategy can be used to fabricate TiO2 nano-trees, which demonstrate high areal/volumetric capacities for lithium-ion micro-batteries.

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