A well-controlled one-step method, assisted by sec-butyl alcohol solvent engineering and N,N-dimethylformamide solvent annealing under an N2 atmosphere, is developed for the growth of a high quality CH3NH3Pb(1−x)SnxI3 perovskite film.

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Syntheses of CaCO 3 crystals in reverse microemulsion solutions containing 1-(1,1,3,3-tetramethylbutyl)-4-hydroxypolyethoxybenzene (Tx-100), sodium dodecyl sulfate (SDS) and their equimolar mixture were carried out at room temperature respectively. The crystal phase of CaCO 3 is changed from calcite at low concentrations to vaterite at high concentrations of SDS and Tx-100. From rods at low concentration to olivary spheres at high concentration, SDS can influence the morphology of CaCO 3 significantly, while almost no such effect for Tx-100. Hollow spheres, olivary spheres and even two fused olivary spheres of CaCO 3 were produced at different concentrations of Tx-100-SDS, and the variation of crystal phase is opposite to that in the presence of SDS or Tx-100 alone. The effects of interaction of SDS with Tx-100 on morphology and crystal phase of CaCO 3 were discussed. It was estimated to put forward that the formation of hollow CaCO 3 crystals was caused by the collaborating actions of SDS template and TX-100 inhibition. morphosynthesis, calcium carbonate, reverse microemulsion, surfactantOne of the most abundant biominerals, calcium carbonate (CaCO 3 ), has attracted much interest due to its applications in paint, plastic, rubber or paper. Its morphologies and crystal phases including calcite, aragonite, and vaterite have been focused on and affected by organic templates or additives. Surfactants are used mostly as template to control the synthesis of crystals with various morphologies, polymorphs and phases due to their influences on one or several crystallization steps (nucleation, crystal growth, aggregation) [1,2] . In aqueous solution, surfactants with different hydrophilic groups resulted in various morphologies and crystal phases of CaCO 3 [3] . SDS is much more effective in producing vaterite than AOT due to a stronger water pool effect in reverse micelle [4] . Hollow spherical particles [3] and spherical particles [4] of CaCO 3 were prepared in aqueous solution and reverse micelle system of SDS, respectively. The solution system influences significantly its morphology [4] . Sponge-like microspheres were prepared by passive evaporation of a supersaturated water-in-oil microemulsion of SDS [5] . Nanowires were formed in reverse micelle system of nonionic surfactant Tx-100 [6] .The reverse micelle appears to be a special circumstance for controlling synthesis of CaCO 3 . The concentration of surfactants plays an important role in transforming its polymorphs from calcite at low concentration to vaterite at high concentration [3,7] . Except template action, surfactant can also form hybrid surfactant-vaterite nanostructures through microemulsion-mediated phase transformation [8] .On the other hand, double-hydrophilic block copolymers (DHBCs) can turn out to be extraordinary effective in unusual morphologies and size control for CaCO 3 [9,10] . The other polymers have also been employed in its crystallization alone [11,12] . Even small molecular organic additives show effects on its crystallization [13,...

A simple, efficient electrochemical assay based on gold nanoparticle dropped TiO 2 microsphere (Au/TiO 2 ) hybrids was developed for the highly sensitive and selective determination of Arsenic (As (III)) by square wave anodic stripping voltammetry (SWASV). An Au/TiO 2 modified glassy carbon electrode (Au/TiO 2 /GCE) possessed a three-dimensional porous structure and exhibited a high active surface area and excellent electron transfer properties. Due to the synergy effect of Au/TiO 2, Au/TiO 2 /GCE greatly enhances the selectivity, sensitivity, and stability of electrodes with respect to the reduction time and composition of the electrodes compared to gold nanoparticle modified GCE (Au/GCE) and TiO 2 modified GCE (TiO 2 /GCE) for detection As (III). The experimental conditions with respect to reduction time and electrolyte were optimized to maximize the sensitivity of the measurement. Under optimal conditions, the SWASV peak current for As (III) concentration was excellent in the range of 1 × 10 −7 to 8 × 10 −6 M. The limit of detection (LOD) of this sensing system was 0.04 μM. Simultaneously, the sensing system's good repeatability and stability prevents the effects of interfering species, which is suitable for As(III) determination in real samples.Arsenic is a highly toxic element and a relatively widespread water pollutant related to different diseases in some countries. 1-7 Investigation has shown that continued consumption of elevated levels of arsenic will caused skin, 8 bladder, kidney, liver, and lung cancers, 9 heart disease, and stillbirth. 7,10,11 Inorganic arsenic exists in ground water mainly as AsO 2− (As (III)) and AsO 4 3− (As (VI)). The former is about 50 times more poisonous than arsenate ions due to its reaction with enzymes in the human metabolism system. 7,10 The maximum As (III) concentration allowed in drinking water as set by the World Health Organization (WHO) is 0.01 μg/L (10 ppb). 12,13 Multiple methods have been used for measuring the level of As (III), 14,15 including atomic absorption spectrometry, 16-20 spectrophotometric, 21-23 fluorescence spectroscopy, 24,25 and inductively coupled plasma-mass spectrometry (ICP-MS). 26-28 These methods were successful in detecting As (III) at sub ppm to sub ppb levels and suitable for laboratory conditions, 14 but their reproducibility is poor and they require timeintensive procedures for pre-separating, 15,29 which requires expensive and sophisticated instruments. Because the presence of As (III) in food or water above a certain level presents a serious threat to public health, it is urgent to develop a simple, low cost, easy operation, highly sensitive, and selective analytical method for determination of trace amounts As (III). 15 Electrochemical methods have received a great deal of attention as a promising source 2 due to the inexpensive instrumentation, portability, extremely high sensitivity, fast response, and low detection limit. 9 Signal amplification is the most popular strategy, and has been extensively used for the development of ultr...

Exploration of low-cost, short-process, environment-friendly, and well-behaved phase change composites is of great significance. The renewable biomass loofah sponge (LS) fibers exhibit superior characteristics such as unique microtubules, substantial micrometer-scale channels, and exceptionally high porosities and have great potential of being utilized to exploit high-performance phase change composites. Herein, we proposed a facile strategy for fabricating a novel shape-stable phase change composite (PCLS) supported by LS fiber microtubules incorporating polyethylene glycol (PEG). The LS fibers with a porous tubular structure provided superior encapsulation and mechanical support for PEG. Encapsulation capacity of LS fibers for PEG was not affected by the duration of vacuum impregnation but increased with the increase in PEG concentration (lower than 0.24 g/mL) and then tended to the maximum of ∼56.5%. Differential scanning calorimetry results showed that the resultant PCLS had a melting/crystallization temperature of 41.7/32.3 °C and a heat enthalpy of 98.9/86.1 J/g, which contributed to great thermal energy storage/retrieval capability. The fabricated PCLS also featured excellent thermal cycling reliability for long-term use. Thermogravimetric analysis results suggested that there were two steps of degradation process for the resultant PCLS and corresponded to the decomposition of PEG and LS fibers, respectively. Infrared thermal images demonstrated that the resultant PCLS showed good infrared stealth ability and could effectively reduce infrared heat radiation. Self-assembly temperature control performance measurement indicated that the fabricated PCLS displayed superior temperature regulation ability. Such innovative PCLS holds great promise for widespread applications in solar thermal-energy storage, thermal regulation, thermal insulation, and thermal camouflage and stealth.