从高钙富硼老卤中提硼研究

以青海某高钙富硼老卤为研究对象开展了提硼研究。结果表明,合适的萃取条件为:磺化煤油为稀释剂、异辛醇用量50%、萃取相比1.0、萃取混合时间15 min;合适的反萃条件为:反萃剂为pH=1的稀盐酸、反萃相比1.5、反萃混合时间15 min。以此条件在5级混合澄清槽中完成了连续逆流萃取—反萃运转试验,连续运转45 h,硼萃取率为95.49%,硼与钾、钠、钙、镁的分离效果较好;硼反萃率为99.59%,反萃液中硼含量达17.17 g/L。采用“溶剂萃取—反萃—高温蒸发—低温冷却结晶—重溶—冷却结晶—过滤洗涤—干燥”工艺高效分离提取硼,硼总回收率为92.33%,制备出的硼酸产品达国家标准(GB/T 538—2018)要求。

大港油田卤水压井液结垢问题治理研究

为解决盐卤水结垢问题,采用三种阻垢剂WJ-1、TJ-302、TS-6对中高密度的盐卤及钙卤进行改性研究,制备出配方并应用于大港油田地区地层水及回注水进行阻垢性能的评价。试验结果表明:两种改性配方钙卤+1%~3%WJ-1+0.2%十二烷基硫酸钠和盐卤+1%~3%WJ-1+1%~3%TS-6+0.2%十二烷基硫酸钠,能使7000 mg/L NaHCO 3和500 mg/L Na 2SO 4地层水在90℃不结垢,钙保留率达到90.0%以上,地层渗透率恢复率达到89%。因此配方适用于高碱高盐的地层,可以解决大港油田卤水压井作业结垢堵塞地层的问题,同时对其他类似地层的油田也有一定指导意义。

Mechanochemical preparation and application of graphdiyne coupled with CdSe nanoparticles for efficient photocatalytic hydrogen production

Graphdiyne(GDY)has attracted considerable attention as a new two-dimensional(2D)carbon hybrid material because of its good conductivity,adjustable electronic structure,and special electron transfer enhancement properties.GDY has great potential in the field of photocatalytic water splitting for hydrogen evolution,owing to its unique properties.In this study,GDY was successfully prepared by the mechanochemical coupling of precursors C_(6)Br_(6) and CaC_(2) using a ball-milling approach.The prepared GDY,especially its microstructure and composition,was well characterized using different techniques such as X-ray diffraction,scanning electron microscopy,transmission electron microscopy,X-ray photoelectron spectroscopy(XPS),Fourier-transform infrared,and Raman characterization techniques.By exploiting the unique two-dimensional(2D)structure and outstanding light absorption properties of GDY,GDY/CdSe 2D/0D heterojunctions were successfully established and applied to photocatalytic hydrogen evolution.The hydrogen evolution activity of GDY/CdSe-20,a type of composite material,reached 6470μmol g^(-1) h^(-1),which is 461 and 40 times higher than that of GDY and CdSe,respectively.Moreover,the fine electrical conductivity of GDY enabled rapid and effective transfer of the photogenerated electrons in CdSe into the hydrogen evolution reaction.The transfer path of the photogenerated electrons was studied through XPS with in situ irradiation,and a reasonable mechanism for the hydrogen evolution reaction was proposed.This study provides a feasible approach for the large-scale preparation of GDY and demonstrates the prospects of GDY in the field of photocatalysis.

Accelerated Interfacial Charge Transfer in Br-Gradient MAPbI_(3-x)Br_(x) Perovskite Thin Films

Mixed halide perovskites(MHPs)are a class of semiconductor materials with great promise for many optoelectronic applications due to their outstanding photophysical properties.Understanding and tailoring the photogenerated carrier dynamics is essential for further improvement of perovskite performance.Herein,we report a study about the carrier transport and interfacial charge transfer dynamics in Br-gradient MAPbI_(3-x)Br_(x) perovskite thin films prepared by surface ion-exchange method.Driven by the bandgap gradient in MAPbI_(3-x)Br_(x) films,the accelerated internal hole transport and enhanced interfacial extraction efficiency were both observed.Meanwhile,the interfacial electron transfer was also found to be evidently facilitated due to the surface modification during post-treatment.Our findings suggest the possibility of simultaneous acceleration of interfacial electron and hole transfer processes in halide perovskite films via surface post-treatment technique,which is of great importance in further improving the power conversion efficiency of perovskite solar cells.

Method for improving illumination instability of organic-inorganic halide perovskite solar cells

Organohalogen perovskites are attracting con- siderable attention for use in solar cells. However, the stability of these devices will determine whether they can be made commercially viable. Device encapsulation or the use of a hydrophobic hole-transporting material can pre- vent the permeation of water into the perovskite layer and enhance the humidity stability of the cells under dark conditions. With regard to the light stability of solar cells, recent studies have yielded contradictory results. This work investigated the degradation mechanism of perovskite solar cells under illumination. Further, a simple method was proposed for improving their illumination stability. Amino acids were inserted between the compact TiO2 layer and the perovskite layer to effectively prevent the decomposition of the perovskite layer owing to the superoxide anions and hydroxyl radicals generated under illumination from the H2O and O2 adsorbed onto the TiO2 layer.

Control of organic–inorganic halide perovskites in solid-state solar cells: a perspective

Since the year of 2009 when the first appli- cation of organohalide lead perovskite as the light har- vester in solar cells was reported, tremendous attention has been devoted to these new types of perovskite-based solid-state solar cells and remarkable power conversion efficiency of over 20 % has been achieved to date. In this review, we first introduce the properties of organic- inorganic halide perovskites and then focus on the notable achievements made on the perovskite layer to improve the power conversion efficiency of solid-state perovskite solar cells, which is featured by process engineering of the state-of-the-art lead methylammoni- um triiodide perovskite and material control of lead triiodide perovskites and other newly emerged per- ovskites. In the end, we wish to provide an outlook of the future development in solid-state perovskite solar cells. Provided that the instability and toxicity of solid- state perovskite solar cells can be solved, we will wit- ness a new era for cost-effective and efficient solar cells.

Exploring stability of formamidinium lead trihalide for solar cell application

Formamidinium lead triiodide （FAPbI3） is a promising photoactive perovskite for low-cost and efficient solar cells. This article reports on an experimental investigation on the stability of FAPbI3 by comparison with that of widely-used methylamidinium lead triiodide （MAPbI3）. A hydration of the FAPbI3 with mois- ture could be the dominant mechanism for its degradation in air, rather than a common thermal decom- position in the MAPbI3. This can be mainly contributed to a relatively strong bond formation between formamidinium ions （FA＋） and 1-. Consequently, the stability of FAPbl3 based devices can be greatly enhanced by removal moisture in the surrounding. This conclusion renders FAPbI3 extremely attractive for stable perovskite solar cells with fine encapsulation.

Anionic surfactant anchoring enables 23.4%efficient and stable perovskite solar cells

Nonradiative recombination losses at defects in metal halide perovskite films are responsible for hindering the improvement of the photovoltaic performance and stability of perovskite solar cells(PSCs).Here,we report a feasible multifunctional additive strategy that uses cesium stearate to passivate defects in perovskite films and simultaneously enhances the tolerance to light and moisture stress.Nonradiative recombination losses are effectively suppressed in target films that exhibit improved crystallinity,low trap-state density,and enhanced carrier separation and transportation.The present strategy hence boosts the power conversion efficiency of the pi-n structured PSC to 23.41%.Our device also shows good stability in ambient air without encapsulation,maintaining 91.6%of the initial efficiency after 720 h.

Organolead trihalide perovskite materials for efficient light emitting diodes

Organolead trihalide perovskite materials have been attracting increasing attention due to their promising role in solid solar cells. Several advantages make them potential candidates for optoelectronics:(1) solution- or/and vapor-processed preparation at low temperature;(2) tunable optical bandgap, wide absorption spectrum but narrow photoluminescence peaks;(3) long car-rier life time, large diffusion length and high charge mobility;(4) various nanostructures via tuning capping agents and sol-vents. In this review, we summarize recent attempts toward efficient LEDs based on organolead trihalide perovskite materials. The strategies of materials science, device design and interface engineering are highlighted. Recent development and future perspectives are summarized for practical perovskite light technologies.

High quality large single crystals of metal halide perovskites for optoelectronic applications

As the technological development of large single-crystalline wafers have revolutionized many industries including electronics and photovoltaics,one can predict that the availability of large single-crystalline perovskite crystals and wafers can revolutionize its broad applications in photodetectors,solar cells,LEDs,lasers,etc.In 2015,Liu et al.