Search

Organic photodetectors (OPDs) have drawn extensive research efforts due to their tailorable spectral response, ease of processing, compatibility with flexible devices and cooling-free operations. In this review, we outline the promising strategies for constructing high-performance and highly stable photodiodes-based OPDs from the perspectives of molecular engineering, morphology control, and device structure design. Firstly, the impact of molecular design and morphology control on OPD performance is clearly underlined and the molecular design rules and quantitative analysis methods are presented for high-performance OPDs. Subsequently, some striking device designs for multifunctional applications are discussed to elucidate the corresponding mechanism for various responses. What follows are the research efforts of boosting OPD stability for commercial applications. This review not only presents the detailed discussion on various OPD strategies aiming at simultaneously enhancing performance and stability but also provides some insights for the remaining challenges to make further breakthrough of OPDs.

Bismuth tungstate (Bi2WO6) has become a research hotspot due to its potential in photocatalytic energy conversion and environmental purification. Nevertheless, the limited light absorption and fast recombination of photogenerated carriers hinder the further improvement of the photocatalytic performance of Bi2WO6. Herein, we provide a systematic review for the recent advances on Bi2WO6-based photocatalysts. It starts with the crystal structure, optical properties and photocatalytic fundamentals of Bi2WO6. Then, we focus on the modification strategies of Bi2WO6 based on morphology control, atomic modulation and composite fabrication for diverse photocatalytic applications, such as organic synthesis, water splitting, CO2 reduction, water treatment, air purification, bacterial inactivation, etc. Finally, some current challenges and future development prospects are proposed. We expect that this review can provide a useful reference and guidance for the development of efficient Bi2WO6 photocatalysts.

Mn-based oxides have been regarded as a promising family of cathode materials for high-performance lithium-ion batteries, but the practical applications have been limited because of severe capacity deterioration (such as LiMnO2 and LiMn2O4) as well as further complications from successive structure changes during cycling, low initial coulombic efficiency (such as Li-rich cathode) and oxidization of organic carbonate solvents at high charge potential (such as LiNi0.5Mn1.5O4). Large amounts of efforts have been concentrated on resolving these issues towards practical applications, and many vital progresses have been carried out. Hence, the primary target of this review is focused on different proposed strategies and breakthroughs to enhance the rate performance and cycling stability of nanostructured Mn-based oxide cathode materials for Li-ion batteries, including morphology control, ion doping, surface coatings, composite construction. The combination of delicate architectures with conductive species represents the perspective ways to enhance the conductivity of the cathode materials and further buffer the structure transformation and strain during cycling. At last, based on the elaborated progress, several perspectives of Mn-based oxide cathodes are summarized, and some possible attractive strategies and future development directions of Mn-based oxide cathodes with enhanced electrochemical properties are proposed. The review will offer a detailed introduction of various strategies enhancing electrochemical performance and give a novel viewpoint to shed light on the future innovation in Mn-based oxide cathode materials, which benefits the design and construction of high-performance Mn-based oxide cathode materials in the future.

Metal-organic frameworks (MOFs) with high designability and structure diversity have been widely developed as promising photocatalytic materials, but most of them suffer from poor charge transportation and separation efficiency. To address it, the construction of MOFs-based heterostructures has been thus highly inspired. In this minireview, we will first introduce the basic principles of photocatalytic water splitting and heterostructure systems, and then discuss state-of-the-art MOFs-based heterostructures for photocatalytic water splitting to produce hydrogen. Meanwhile, special attention will be paid to the key factors affecting the interfacial charge transfer of heterostructures, such as interface connection mode, morphology control, and modification. Eventually, the challenges and prospects faced by the construction of high-efficiency MOFs-based heterostructure water slitting photocatalysts are proposed.

With the development of the preparation methods of low dimensional materials, one-dimensional (1D) nanomaterials present enormous benefits in hydrogen sensing area. This work reviews the up-to-date research progress of 1D nanomaterials in the field of hydrogen gas sensing and its three routes via material, morphology and post-treatment to enhanced sensing performances. Besides, the mechanism of hydrogen gas sensing, the differences of enhancement effect between material synthesis, morphology control and post-treatment schemes are analyzed. Finally, the prospects and challenges of 1D nanomaterials in hydrogen gas sensing are discussed and outlooked.

Al-ion batteries (AIBs) have been identified as one of the most hopeful energy storage systems after Li-ion batteries on account for the ultrahigh volumetric capacity, high safety and low cost from the rich abundance of Al. Nonetheless, some inevitable shortcomings, such as the formation of passive oxide film, hydrogen side reactions and anode corrosion, finally limit the large-scale application of aqueous AIBs. The nonaqueous AIBs have been considered as one of most hopeful alternatives for high-powered electrochemical energy storage devices. Nonetheless, various technical and scientific obstacles should be resolved because nonaqueous AIBs are still nascent. Some significant efforts have aimed to resolve these issues towards large-scale applications, and some important advancement has been made. In the present review, we mainly intended to offer an overview of non-aqueous AIBs systems, and we comprehensively reviewed the recent research advancement of the cathode materials, anode materials electrolyte and collectors as well as the fundamental understanding of the functional mechanisms. In addition, we have also analyzed several technical challenges and summarized the strategies used for overcoming the challenges in improving the electrochemical properties, including morphology control, surface engineering, doping and construction of composite electrodes as well as the charge storage mechanisms of the materials with different crystal structures. At last, future research orientation and development prospect of the AIBs are proposed.

In the last decades, magnetic ceramics are very appealing materials that find applications in several technologic fields. Among these, iron oxides nanoparticles are the main relevant ones due to their low-cost as naturally occurring substrates. However, depending on the application, it can be necessary to induce a specific shape and size control over the final morphology, and consequently a proper synthetic route becomes mandatory. Hence, this document provides a summary of the main relevant chemical, physical, thermal, and biological methods to induce a certain degree of morphological control in iron oxides. The main focus of this document relies on highlighting the principal guidelines, unveiling both advantages and disadvantages of each method in terms of morphology control in the resulting products. Lastly, a particular emphasis has been dedicated toward the industrial feasibility of all processes here discussed. Resumen: En las últimas décadas, la cerámica magnética es un material muy atractivo que encuentra aplicaciones en varios campos tecnológicos. Entre estos, las nanopartículas de óxidos de hierro son las principales por su bajo costo como sustratos naturales. Pero, dependiendo de la aplicación, puede ser necesario inducir un control de forma y tamaño específico sobre la morfología final y, por lo tanto, una ruta sintética adecuada se vuelve obligatoria. Por esta razón, este documento ofrece un resumen de los principales métodos químicos, físicos, térmicos y biológicos relevantes para inducir un cierto grado de control morfológico en los óxidos de hierro. El objetivo principal de este documento se basa en resaltar las principales directrices, revelando las ventajas y desventajas de cada método en términos de control de la morfología en los productos resultantes. Por último, se ha dedicado un énfasis particular a la viabilidad industrial de todos los procesos aquí discutidos.

Doughnut-shaped t-LuPO4 microparticles (∼1.3−1.5 μm in diameter and 1.1–1.3 μm thick) were originally synthesized via lactic acid (LA) assisted solvothermal reaction, and the effects of LA content and PO43−/Lu3+ molar ratio on phase/morphology evolution were thoroughly investigated. It was demonstrated that LA significantly altered the intrinsic crystallization habit of t-LuPO4 and simultaneously promoted 2D growth and 3D self-assembly of the crystallites. The synthesis strategy was also shown to be well extendable to the other t-REPO4 of RE = Ho-Yb and Y. With t-LuPO4 as a representative host, the down-conversion photoluminescence properties (excitation/emission, florescence decay, quantum efficiency) of Sm3+, Dy3+, Tb3+, Eu3+ and Tb3+/Eu3+ pair were thoroughly investigated. For the series of t-(Lu0.98-xTb0.02Eux)PO4 (x = 0−0.12) ternary phosphors, color-tunable emission (from green to red) was obtained through Tb3+ → Eu3+ energy transfer, and the optimal Eu3+ content was determined to be x = 0.08 for the total luminescence of Eu3+ and Tb3+. Under 978 nm laser excitation, t-(Lu0.88Yb0.10Er0.02)PO4 phosphor was found to exhibit strong green (522/547 nm; 2H11/2/4S3/2 → 4I15/2) and red (655/665 nm; 4F9/2 → 4I15/2) up-conversion luminescence via a two-photon process. The merits of the morphology control of this work were also clearly demonstrated by comparing the luminescence performances of Eu3+ in microdoughnut particles and nanoparticles synthesized without LA.

Advances in nanoscience and nanotechnology have brought the need to make the nanoparticles preparation friendlier to the environment. The great variety of applications involving magnetite nanoparticles justifies a growing need for greener synthetic routes. A green approach for preparing nanoparticles is based on the use of plant extracts. In this minireview, the current plant-mediated strategies for preparing magnetite nanoparticles are briefly described and the main features (size, morphology, magnetic properties) of the obtained nanoparticles. The advantages and drawbacks of using those procedures are also highlighted.

MXene materials with efficient electromagnetic (EM) microwave absorber applications are in high demand. Herein, the EM wave absorption properties of two-dimensional MXene Ti3C2Tx, fabricated by etching the Ti3AlC2 phase with an enchant of HCl and LiF, was thoroughly investigated over a frequency range of 2–18 GHz. In addition, the impact of three critical factors (reactant concentration, reaction time, and reaction temperature) on the morphology control and dielectric properties was discussed. With increasing degree of exfoliation, the multilayer structure of Ti3C2Tx changed gradually, thereby further influencing the microwave absorption properties. Among the etched samples, Ti3C2Tx prepared with 9 M HCl at 35 °C for 24 h exhibited an excellent reflection loss of −40.8 dB at 13.9 GHz with a thickness of 1.45 mm, while also possessed the broadest effective bandwidth, reaching 3.66 GHz at 1.68 mm. The demonstrated EM wave response mechanism, indicated that the conduction loss and polarization loss contribute significantly to the EM wave absorption performance. These findings endow the Ti3C2Tx material with an effective foundation for the construction of novel EM wave absorbers.

A feasible method has been developed for the morphology control of ordered supermicroporous silicas by adopting a kind of rosin-based surfactant as the templating agent. By adjusting the molar ratio of sodium silicate (SS) and ethyl acetate (EA), the morphologies of the materials can be changed from hollow sphere to hollow tube, and solid rod, while the degree of ordering of the samples showed a trend of firstly increasing and then decreasing. When the molar ratio of SS/EA was 0.38, an ordered supermicroporous silica with a hollow tubular morphology was obtained. The material had a surface area of 645.5 m2/g, a pore volume of 0.3 cm3/g, and a pore size distribution centered at 1.8 nm. When the molar ratio of SS/EA was increased to 0.46, the resulting sample exhibited a solid-rod morphology with a highly ordered hexagonal supermicroporous structure. This material had a large surface area of 1478.1 m2/g, a high pore volume of 0.7 cm3/g, and a uniform pore size distribution centered at 2.0 nm.

Increasing demands for detection of toxic gases have attracted more and more attention to design and fabricate gas sensors with properties of ppb-level detectable, good selectivity, and long-term stability. In this paper, Prussian blue (PB) was utilized as precursor for preparation of Fe2O3. The morphology of PB was well tuned by different surfactants and synthesis temperatures, and following with calcination at 550 °C transformed them into Fe2O3 without changing the primary morphologies. The gas sensing properties of these as-prepared Fe2O3 materials were systematically tested. At the optimum operation temperature (200 °C), the sensors based on Fe2O3 nanocubes, nanospheres, and nanoflowers can detect H2S at ppb-level with low cross-sensitivity and excellent long-term stability. Experimental results reveal that the nanospheres based sensor have the best sensing performance, which follows the order nanospheres >nanocubes >nanoflowers. The results demonstrate that it is effective to improve the properties of metal oxide based gas sensor through morphology control by metal organic frameworks (MOFs)-templated route.

Two-dimensional (2D) metal-organic frameworks (MOFs) and covalent-organic frameworks (COFs) have recently emerged as a new class of crystalline materials with ultrahigh porosity and enormous surface area. These materials have attracted vast research interest due to their unique properties originating from ultrathin thickness, highly accessible active sites, and versatile structures. With many common features, MOFs and COFs also have distinct differences, both in synthetic and application aspects, as their building components are different. This review mainly focuses on the recent advances in the synthetic approaches of 2D MOFs and COFs and their applications in energy conversion reactions and storage devices. First, we discuss various strategies recently developed for the preparation of 2D MOFs and COFs by using self-assembly, template-directed method, surfactant-directed method, solid-supported growth, and decomposition, and the different considerations needed for desired 2D MOFs and COFs are compared. Secondly, energy-related applications of 2D MOFs and COFs are summarized with discussion on the structure-reactivity relationships. Finally, we give the insights into the challenges and outlook on the future research direction for 2D MOFs and COFs.

Microfluidic systems have unique advantages originating from the miniaturization of real chemical processes. On this basis, the synthesis of inorganic materials, including micro- and nanomaterials, can be used to develop useful features, such as a uniform particle size distribution, morphology control, online monitoring, etc. In this review, we introduce and discuss the recent progress in the preparation of inorganic materials, mainly microfluidics systems. Furthermore, utilizing microfluidic devices, we present the basic principles and representative shape of microfluidic systems. In addition, the synthesis of various inorganic material particles using microfluidic systems, such as metal nanoparticles, metal oxide nanoparticles, semiconductor nanoparticles, organic-inorganic hybrid particles, surface functionalized particles, core-shell particles, and traditional porous materials, is introduced. Finally, we propose the future prospects of microfluidics in the synthesis of noble inorganic materials.

Over the past decade, a wide range of nanomaterials have attracted extensive attention for artificial enzymes (nanozymes) to meet task-specific applications because of their intrinsic enzyme-like catalytic activities. Artificial enzymes based on inorganic nanomaterials are now envisioned as an increasingly relevant alternative to traditional natural enzymes due to their structure robustness, unusual high catalytic performance, facile synthesis from inexpensive and abundant raw materials. This tutorial review summarizes and highlights latest progress in design and construction strategies of inorganic nanomaterials to mimic the structure and functionality of natural peroxidase with a focus on optical technique, both the existing research hotspots and future prospects are outlined and discussed. Furthermore, methodologies for tailoring nanomaterials-based intrinsic peroxidase mimics to enhance their catalytic activity including morphology control, surface modulation and heterostructure coupling are also summarized. Finally, we put forward our personal insights into future research challenges and opportunities, hoping to motivate more researchers to participate in the research in this emerging field.

NaTi2(PO4)3 (NTP) nanocrystals with high room-temperature ionic conductivity of 1.1 × 10−3 S/cm were prepared by a concise solvothermal method at 140 °C for 3 h, and the aspect ratios of all the NTP nanocrystals are the closest to 0.7. It implies a moderate size-distribution of NTP nanocrystals obtained at 140 °C for 3 h is helpful for increasing packing density, and the packing density is the larger, so its conductivity is the higher. The controllability over size and morphology of the NTP nanocrystals via solvothermal temperature and time were investigated. The results suggest that our method is of great potential in synthesizing NTP nanocrystals with high room-temperature ionic conductivity at low cost.

Solvent additive can effectively regulate the phase-separated morphology of the active layer and improve the power conversion efficiency of polymer solar cells. In this study, the influence of solvent additives 1,8-dichlorooctane (DClO), 1,8-dibromooctane (DBrO) and 1,8-diiodooctane (DIO) on the morphology of PTB7:PC71BM active layer films is investigated systematically, and the photovoltaic performance of the prepared bulk heterojunction polymer solar cells is analyzed detailedly. The DIO and DBrO additives facilitate PC71BM diffusing into the PTB7 polymer network and forming interpenetrated bulk heterojunction junction morphology, while the DClO additive deteriorates the active layer morphology. The optimized morphology of DIO and DBrO additives promotes exciton dissociation efficiency, improves charge transport and collection efficiency. The optimum performances were obtained in the devices with DIO additive.

The effluent associated with mercury and arsenic has attracted a wide concern due to their high hazardous risk to human beings and the environment. In this study, the layered double hydroxides (LDHs) loaded/coated [SnS4]4- ([SnS4]4-@MgFe-LDHs and [SnS4]4-/MgFe-LDHs) materials were prepared for Hg(II) and As(III) selective adsorption under various conditions. The results shown that morphology controlling method could adjust the selective adsorption of Hg and As. For Hg(II) removal, the [SnS4]4-@MgFe-LDH was 50.5% and the [SnS4]4-/MgFe-LDH-1, -2, and -3 was up to 92.9%, 97.1% and 71.4%, respectively. And the adsorption behavior of Hg(II) transformed from the physical adsorption ([SnS4]4-@MgFe-LDH) to the chemical adsorption ([SnS4]4-/MgFe-LDHs), which profited from the regulation of surface enhancing the exposed S active sites. However, for As(III) removal, the [SnS4]4-@MgFe-LDH was 47.6%, while the three different [SnS4]4-/MgFe-LDHs were down to both approximately 20%. The adsorption kinetics study confirmed that the As(III) adsorption was complex and contained both chemical and physical adsorption. Furthermore, for the [SnS4]4-@MgFe-LDH, [SnS4]4-/MgFe-LDH-1 and -3, the physical adsorption was the dominated process, while the [SnS4]4-/MgFe-LDH-2 enhanced the chemical adsorption process due to the urchin-like morphology with rough surface that exposing more active sites. Therefore, different morphology control methods realized high efficient removal of As and Hg ions.

Green synthesis approaches of nanomaterials (NMs) have received considerable attention in recent years as it addresses the sustainability issues posed by conventional synthesis methods. However, recent works of literature do not present the complete picture of biogenic NMs. This paper addresses the previous gaps by providing insights into the stability and toxicity of NMs, critically reviewing the various biological agents and solvents required for synthesis, sheds light on the factors that affect biosynthesis, and outlines the applications of NMs across various sectors. Despite the advantages of green synthesis, current methods face challenges with safe and appropriate solvent selection, process parameters that affect the synthesis process, nanomaterial cytotoxicity, bulk production and NM morphology control, tedious maintenance, and knowledge deficiencies. Consequently, the green synthesis of NMs is largely trapped in the laboratory phase. Nevertheless, the environmental friendliness, biocompatibility, and sensitivities of the resulting NMs have wider applications in biomedical science, environmental remediation, and consumer industries. To the scale-up application of biogenic NMs, future research should be focused on understanding the mechanisms of the synthesis processes, identifying more biological and chemical agents that can be used in synthesis, and developing the practicality of green synthesis at the industrial scale, and optimizing the factors affecting the synthesis process.

Propionic acid could efficiently affect the formation of Cr-benzenedicarboxylate metal-organic frameworks (MOFs), giving rise to yielding products with various structures. Generally, nano-sized crystals of MIL-101(Cr) can be prepared with comparatively lower concentration of propionic acid (0.6 ​M), which possessed high porosity (SBET ​= ​2720 ​m2/g). The hierarchically porous (HP) MIL-101(Cr) was obtained with medium concentration of propionic acid (1.2 ​M), and micro-rod like crystals of MIL-88B(Cr) was formed in high concentration of propionic acid (1.8 ​M). Compare to bulk MIL-101(Cr) and nano-sized MIL-101(Cr), HP-MIL-101(Cr) showed much higher uptake of methylene blue (119.1 ​mg/L) in aqueous. This approach can offer a facile and effective pathway to synthesize stable hierarchically porous Cr-benzenedicarboxylate MOF for the applications in pollutant treatment fields.

Indium vanadate (InVO4) is an up-and-coming semiconductor photocatalyst for energy/environment-related applications, and has attracted tremendous attention in the last few decades, owing to its suitable band gap, high thermal and chemical stability, and outstanding photocatalytic performance. However, the low solar-energy utilization efficiency of InVO4 material constrains its further development, mainly due to the sluggish separation and migration kinetics of charge carriers. Fortunately, recent breakthroughs have been achieved in both enhancing the efficiency and clarifying the underlying mechanism for photocatalytic applications. Therefore, it is necessary and urgent to summarize these research efforts and breakthroughs upon InVO4-based nanomaterials to improve the photocatalytic efficiency and speed up the commercialization. In this review, we systematically summarize the recent experimental and computational developments of the modifications of InVO4-based photocatalysts by morphology control, element doping, and hetero-junction construction. Then, we give an overview of their promising photocatalytic applications. Finally, the perspectives on the challenges faced and potential future research directions on InVO4-based photocatalysts is given. We aim to provide guideline for the rational design and fabrication of high efficient InVO4-based photocatalysts for energy and environmental applications.

Lithium-ion batteries (LIBs) are considered as a promising power source for electric vehicles and electronic products such as mobile phones, laptops, and tablets. The anode material plays a crucial role in the reliability and safety of LIBs. Among the anode candidates, MLi2Ti6O14 (M = 2Na, Sr, Ba, Pb) materials have very good prospects due to their excellent safety, good structure stability, negligible volume change, and suitable voltage plateau of about 1.3–1.4 V (vs. Li0/Li+). However, MLi2Ti6O14 materials frequently sustain serious capacity decay at high rate due to the poor electronic and ionic conductivities. Therefore, it is very meaningful to summarize comprehensively and scientifically the advances of this material family from all aspects. The main objective of the review is aimed to summarize various proposed strategies (i.e. material treatment, morphology control, surface modification, and cation doping) and the breakthroughs to enhance the rate capacity and cycling stability of the MLi2Ti6O14 materials. The review will provide some insights into the structures and performance issues, which will be helpful for the design and optimization of the MLi2Ti6O14 materials.

In this article we report an in-situ catalytic strategy for homogeneous dispersion of β-nucleating agent N,N′-dicyclohexyl-terephthalamide (DCTPA) into isotactic polypropylene (iPP) as well as morphology control of the DCTPA/iPP composites. This strategy is based on catalyst to polymer morphology replication approach, in which by embedding Ziegler-Natta catalyst species on DCTPA surface, the fresh iPP chains first grew on the DCTPA tiny crystals and then wrapped about them; thus the interaction between DCTPA crystals and iPP matrix was enhanced, and the thermodynamic barrier of dispersing DCTPA in the inert iPP was avoided. The dispersion morphology and the self-assembly/recrystallization morphology of DCTPA in iPP were investigated; the relationship between DCTPA/iPP composites micro-structures and their crystallization behaviors was compared with that of the melting-blended DCTPA/iPP systems. Due to the improvement of DCTPA dispersion and the enhancement of interaction between DCTPA and iPP melts, the synthesized samples presented characteristics of fast crystallization initiation and slow spherulites growth rate, which is different from the general melting-blended composites.

In this study, carbon nanotube (CNT) hybrid aerogels with high mechanical properties were fabricated by interconnecting structural networks of CNTs using poly(vinyl alcohol) (PVA) through amine-functionalized iron oxide (NH2-Fe). Consequently, Fe-CNT-PVA hybrid aerogels exhibited good structural stabilities, even under repeated loads due to the interconnection bonding with PVA between neighboring CNTs. Furthermore, compared to the Fe-CNT aerogels, the Fe-CNT-PVA hybrid aerogels showed ∼3 times higher specific surfaces due to the tuning of the internal morphology by controlling electromagnetic interactions between NH2-Fe on the surface of the CNTs and the applied magnetic field. These results clearly show that CNT aerogels with both improved structural stabilities and specific surface areas can be fabricated by the method proposed in this study.

Homojunction construction is attractive for developing high-performance semiconductor photocatalysts. In this study, a facile combination process was employed for the first time to fabricate the Ag3PO4 morphological homojunction consisting of submicron spherical and rhombic dodecahedron particles, which could achieve morphology control and homojunction manipulation simultaneously. The enhancement of photocatalytic activity was attributed to that the formation of morphological homojunction which consists of rhombic dodecahedral Ag3PO4 (RDA) and submicron spherical Ag3PO4 (SSA) with different band structures, which promotes efficient separation of photogenerated electron-hole pairs and leads to high photocatalytic activity. The different band structures of Ag3PO4 indicate that morphology affects the valence and conduction band position of semiconductors, and further verifies the formation of morphological homojunction. The finding of our work illustrated that the fabrication of Ag3PO4 morphological homojunction was a promising strategy to be applied in photocatalysis and photoelectric conversion.

This study aimed to verify CO2 reduction and morphological control of its precipitates by applying the CO2 mineralization mechanism under ambient conditions. In the first stage, CO2 absorption-conversion experiments were performed using three types of amines (mono-ethanolamine, MEA; di-ethanolamine, DEA; and methyl-di-ethanolamine, MDEA) to improve the rate and efficiency of CO2 conversion into metal carbonates. In the second stage, CO2 was re-absorbed and supplied as aqueous CO2, forming MgCO3 and MgCO3(H2O)3 precipitates. The formed MgCO3 was analyzed by X-ray diffraction (XRD) and field emission scanning electron microscope (FE-SEM). In particular, MgCO3 was formed only in the MEA solution although other amines were exposed to the same experimental conditions. Therefore, the results showed that the CO2 precipitate morphology could be controlled by the type of the conversion solution used. This study has significance regarding CO2 reduction and utilization because the emitted CO2 could be stored semi-permanently. Furthermore, the formed MgCO3 could be re-used in various industries through morphology control. Therefore, this study verified the potential of the CO2 mineralization mechanism for CO2 reduction and morphology control.

The morphology of nanomedicines has a large influence on the anticancer efficiency of therapeutic agents in biological systems. In this study, camptothecin (CPT)-based nanodrugs with helical and spherical shapes were simply built without the need of any additional carriers. Self-deliverable spherical nanodrug represented a therapeutic advantage over the helical one, which was uncovered from the in vitro toxicity assay. Confocal imaging study indicated that the better outcome of spherical nanodrug was ascribed to the faster cellular uptake. With the aid of sonication treatment, helical nanodrugs with different lengths (HD-1, HD-2, HD-3, HD-4) were created. In comparing with the longest HD-1, the drug release kinetics indicated that the shortest HD-4 exhibited a 20% elevation in cumulative drug release at the first 10 h. The internalized drug amount of HD-4 was three-fold higher than that of HD-1 after the cultivation with 4T1 cells for 2 h. These results demonstrated that the anticancer efficacy of helical nanodrugs was inversely proportional to their lengths. The strategy demonstrated here presents great promise for the preparation of nanodrugs with suitable morphology for cancer therapy.

Bismuth vanadate (BiVO4) is a promising visible-light driven semiconductor photocatalyst with various benefits such as low production cost, low toxicity, high photostability, resistance to photo-corrosion and narrow band gap with a good response to visible-light excite. However, the fast recombination of photoinduced charge carriers restricts their photocatalytic activity. In the past decades, many attempts were adopted to enhance the photocatalytic activity of BiVO4. Significant advances in understanding the fundamental issues and the development of an efficient photocatalyst have been made in current years. In this review, we have provided a comprehensive overview of the latest progress on the morphology control and growth mechanism of BiVO4 micro/nano-structures, doping with metal and non-metal elements and semiconductor coupling along with some highlights in the photodegradation of organic pollutants under visible-light illumination. This review may benefit the researchers and engineers in the arena of material chemistry for designing new BiVO4 based photocatalysts with low production cost and high efficiency.

This review summarizes the development, investigation, and optimization of polymorphic lithium cobalt phosphate LiCoPO4. One of the three polymorphs known to date, olivine-type or Pnma-LiCoPO4, shows intriguing electrochemical properties as a high-voltage cathode material, which are of interest for next-generation lithium-ion batteries with higher energy density. Hence, scientists have developed optimization strategies to improve its performance for commercial applications. Herein, a number of procedures for the synthesis of Pnma-LiCoPO4 is presented, including thermodynamic as well as kinetically controlled approaches. The continuous improvement of its electrochemical performance is illustrated, which was realized by the development of solvothermal techniques that allow a precise particle size and morphology control. In the course of these investigations, two new polymorphs, Pna21-LiCoPO4 and Cmcm-LiCoPO4, have been discovered which show different physical and structural properties compared to Pnma-LiCoPO4. Despite their significantly poorer electrochemical performance, these polymorphs allow interesting insights into the variable structure chemistry of transition-metal phosphates, which canalizes in intriguing magnetic and thermal properties. The similarities and differences in the chemical and physical properties of Pnma-LiCoPO4, Pna21-LiCoPO4, and Cmcm-LiCoPO4 are discussed.

Synthesis of conducting polymer-silica colloidal nanocomposites has been recognized as an effective method to overcome the poor processability of heterocyclic conducting polymers prepared by chemical oxidative method. However, the morphology control of such conducting polymer-silica nanocomposites was seldomly reported in the literature. Novel poly(2-aminothiazole)(PAT)-silica nanocomposite particles can be conveniently prepared by chemical oxidative polymerization of 2-aminothiazole using CuCl2 oxidant in the presence of ∼20 nm silica nanoparticles. The effects of varying the oxidant/monomer ratio and silica sol concentration on the morphology and size of the resulting PAT-silica nanocmposites have been studied. Optimization of the oxidant/monomer molar ratio and initial silica sol concentration allows relatively round spherical particles of 150–350 nm in diameter to be achieved. The nanocomposite particles have a well-defined raspberry-like morphology with a silica-rich surface, but a significant fraction of PAT component still exists on the surface and, which is beneficial for its applications. Furthermore, the surface compositions of the colloidal nanocomposites could be regulated to some extent. Based on the above results, a possible formation mechanism of the spherical nanocomposite particles is proposed.

In this study, we propose and demonstrate a novel methodology to fabricate nanomaterials with predictable morphologies and physical/chemical properties. This new fabrication methodology typically comprise the following steps: (i) precursors with specific morphology are coated with mesoporous silica; (ii) the precursors are converted into the target products chemically through the channels of mesoporous silica; (iii) the silica coating shells are removed by NaOH solution or other solutions, leading to the final product. The morphology of the final product is insensitive to external experimental conditions, and only determined by the morphology of the precursors. As a test vehicle, uniform Bi0.96Eu0.04PO4 nanospheres with high light emission efficiency have been successfully fabricated by using Bi0.96Eu0.04 nanospheres as the precursors. This novel fabrication methodology can also be extended to design and fabricate nanomaterials with controlled morphology in other material systems.

In the last few years, the performance of organic solar cells (OSCs) based on bulk heterojunction (BHJ) structure has remarkably improved. However, for a large scale roll to roll (R2R) manufacturing of this technology and precise device fabrication, further improvements are critical. This article highlights the fundamentals of a BHJ OSC, including its working principle and performance characteristics. The importance of stability for the device lifetime is underpinned and different degradation factors affecting the operational life of OSCs are discussed. Lastly, the strategies to improve the stability of OSCs, including the encapsulation of device, morphology control in BHJ layer, interfacial engineering in terms of buffered layers, use of inverted geometry and alternative electrode materials are highlighted. Moreover, a simple mathematical model of degradation trends in OSCs is proposed. This review provides a comprehensive insight into the current status of BHJ OSCs regarding stability/degradation and covers almost all critical aspects that are considered important to understand it.

A flower-like Bi2WO6-Bi2O3 photocatalyst was prepared by a two-step process, including an ionic liquid-assisted solvothermal step and calcination. The effects of the ionic liquids and calcination on the morphology, property, and photocatalytic performance of Bi2WO6-based photocatalysts were studied. The addition of ionic liquids during the preparation of Bi2WO6 based-materials lead to increased sizes of photocatalysts and the formation of more petal sheets in the flower-like microspheres. The results of XRD, XPS, and TEM confirm that Bi2WO6-Bi2O3 photocatalysts formed after the calcination treatment of Bi2WO6 photocatalyst in an air atmosphere. The Bi2WO6-Bi2O3 flower-like photocatalyst exhibits better photocatalytic H2 production activity than the Bi2WO6 photocatalyst. The improved activity of the Bi2WO6-Bi2O3 photocatalysts was attributed to their enhanced light absorption, increased surface area, matched band structure, and the inhibited recombination of the photogenerated charge carriers.

The pollution of water bodies by residual pharmaceuticals is a major problem globally. Bismuth tungstate mediated photocatalysis has been effective in the removal of these organics from water. Bismuth tungstate (Bi2WO6) has proven to be an excellent visible light active photocatalyst because of its non-toxicity, low band gap energy and ease of preparation. It has been widely applied for the removal of a wide array of organic pollutants, particularly dyes, from wastewater. However, recently, much attention has been channelled to its application for the degradation of pharmaceuticals. In this present review, the recent trends in the applications of Bi2WO6 based photocatalysts for the removal of pharmaceuticals in wastewater are comprehensively discussed. The fabrication of Bi2WO6 based photocatalysts with enhanced photocatalytic performances through morphology control, doping and formation of heterojunctions are highlighted. Much discussion centres on the mechanisms and possible degradation pathways of antibiotic pharmaceuticals in wastewater. Finally, areas needing more attention and investigation on the use of Bi2WO6 based photocatalysts for removal of pharmaceuticals from wastewater especially towards real-life applications are presented for future research directions.

Monoclinic-phase BiVO4 is one of the most promising photoanode materials for solar water splitting. Besides commonly applied strategies of morphology control, dopant/defect engineering, and electrocatalyst deposition, the introduction of WO3 underlayers has afforded desirable performance improvements in BiVO4 photoanodes. However, the fundamental issue regarding how the material properties of WO3 underlayers affect the photoelectrochemical behaviors of BiVO4 photoanodes is not clearly understood so far. Herein, crystallinity- and thickness-varied WO3 underlayers are established to analyze their contributions to the performance of BiVO4 photoanodes. The results show that surface defects, electron transferring capabilities of WO3 underlayers, and the coverage ratios of conducting substrates by them are key parameters to consider for the construction of efficient BiVO4 photoanodes. This study presents a deeper understanding on the functions and promotional effects of WO3 underlayers for BiVO4 photoanodes, and will also provide valuable guidelines for the design and optimization of other photoelectrodes toward efficient solar energy conversion.

Multinary quantum dots (QDs), owing to the large degree of freedom in their structure and composition, have a wide tunability in their bandgap and show an increased indeterminacy and complexity in their optical properties. In this work, a facile microwave-assisted aqueous route using sodium citrate and thioglycolic acid (TGA) as dual stabilizer was utilized to synthesize Cu−In−S/ZnS (CIS/ZnS) core/shell QDs. The effects of the shell thickness, refluxing time, pH value, temperature, Cu/In ratio and stabilizer on the morphology and optical properties of the CIS/ZnS QDs have been systematically investigated. The results show that the morphology-controllable alloyed CIS/ZnS QDs with tunable emission from 533 nm to 666 nm and long PL lifetime can be obtained by varying the molar ratio of sodium citrate to TGA. The proposed microwave-assisted aqueous synthesis method for alloyed QDs is simple, rapid, with comparatively low reaction temperature. The as-prepared QDs with the size of 3.8 nm are promising materials for lighting and biological applications.

Spin coated perovslcite thin films are known to have an issue of pinholes & poor morphology control which lead to poor device-to-device repeatability, that is an impediment to scale-up. In this work, Methylamine vapor annealing process is demonstrated which consistently leads to high-quality perovskite thin-films with an average grain-size of 10-15 mu m. The improvement in film morphology enables improvement in effective carrier recombination lifetime, from 21 its in as-deposited films to 54 mu s in vapor-annealed films. The annealed films with large-grains are also more stable in ambient conditions. Devices made on annealed perovskite films are very consistent, with a standard deviation of only 0.7%. Methylamine vapor annealing process is a promising method of depositing large-grain CH3NH3PbI3 films with high recombination lifetime and the devices with improved performance. (C) 2017 Elsevier B.V. All rights reserved.

Hierarchical β -NaGdF 4 nanobundles are synthesized through a facile hydrothermal method with the use of sodium acetate (NaAc). A NaGdF 4 -GdF 3 -NaGdF 4 products transformation with the increase of fluoride source (NaF) is observed. Results show that NaAc is the key factor in the synthesis of β -NaGdF 4 at a low NaF/Gd 3+ ratio and NaAc also plays a significant role in the formation of the hierarchical morphology. Meanwhile, the size of nanobundles increases with the increased ratio of NaF/NaAc. With altering the ratio of reactants, dumbbell-like, urchin-like or rod-like β -NaGdF 4 nanobundles are obtained. The photoluminescent properties of β -NaGdF 4 : 2%Eu 3+ are also measured.

This paper designs and regulates unique monodisperse Fe3O4 hollow spheres through solvothermal method. Hollow structure provide light-weight property which is required for electromagnetic wave (EMW) absorbing materials. First and foremost, the size (700–350 nm) and surface of Fe3O4 hollow spheres can be adjusted by different urea contents, which realizes the morphology control of “big to small” and “smooth to rough”. Secondly, we select different reaction time to study how morphology of Fe3O4 hollow sphere changes, such as the flower-like (F6, 24 h). Thirdly, our work explores the relationship between morphology and property. In addition, the data shows the “double peaks” characteristic of EMW absorption. Overall, the sample F2 has the balance of bandwidth (4.56–9.24 GHz, 4.68 GHz), thickness (3.62 mm) and RL value (−56.90 dB, at 8.32 GHz), leading excellent performance. Finally, Fe3O4 hollow spheres may be widely applied not only in EMW absorption but also in energy storage, biomedical field, etc.

Droplet-based microfluidics offers an effective approach for overcoming the drawbacks of high viscosity and costs of ionic liquids (ILs) in practical applications. However, studies on the hydrodynamic behavior of the formation of IL-based Janus microdroplets which can facilitate the multifunctional applications of ILs through unique structures, are still limited due to their complex interfacial properties and high viscosities. Here, magnetic ionic liquid (MIL)-water Janus droplets were generated in an assembled co-flowing 3D-printed microchannel. Seven typical flow patterns of MIL-water Janus droplet generation were presented in a mountain-shaped flow pattern diagram, which was compared to the flow regime demarcations of MIL single-phase droplet formation. The scaling law of MIL-water Janus droplet size was analyzed to further reveal the breakup mechanism of biphasic dispersed phases with large differences in viscosities and interfacial tensions. Besides, the morphology control of surfactant-free MIL-water Janus droplet in the microchannel was investigated qualitatively and quantitatively. And, by changing the continuous phase, the morphology evolution of MIL-water Janus droplet to core-shell structure was also observed. The present study would be useful for providing a deep and comprehensive understanding on the formation and structure control of IL-based Janus microdroplets which are promising candidates for the use in applications of catalysis and extraction.

Porous carbon materials have been widely reported on dealing with the electromagnetic (EM) wave interference. However, monotonous EM loss mechanism still performed an obstacle to achieve exceptional absorption. In this paper, a series of three-dimensional porous carbon·@PANI (polyaniline) composites were synthesized via facile roasting and subsequent coating process. The morphology, nanostructure and EM wave absorption properties of porous carbon@PANI (PC@PANI) were discussed in detail. Obviously, porous carbon derived from EDTA-2Na coated by PANI (PC@PANI-2) composites exhibited significantly enhanced EM wave absorption performance compared to pure porous carbon. The widest absorption bandwidth (RL

Zn2+-based electrochromic is a newly born technology in recent years and has attracted the attention of most researchers due to its low cost and high safety. The design of high-performance Zn2+-based electrochromic devices, such as large light modulation and fast color change, is still a challenge. Here, we report the improvement of Zn2+-based electrochromic properties by morphology control, using common electrochromic material WO3 as the research model. The hexagonal WO3 films with shape of nanorods and nanoflakes were prepared by hydrothermal method, where the diameter of the nanorods and the thickness of the nanoflakes are almost the same. The electrochromic characterization of WO3 nanorods and nanoflakes at 550 nm showed that their modulation ranges were 72.4% and 61.0%, their coloration times were 3 and 9 s, their bleaching times were 2.2 and 7 s, and their coloration efficiencies were 67.6 and 53.8 cm2 C-1, respectively. Compared with WO3 nanoflakes, the excellent Zn2+-based electrochromic properties of WO3 nanorods show rapid electron transfer kinetics caused by large surface area. Furthermore, the prototype electrochromic devices with WO3 nanorods were fabricated, which showed good specific capacitance and excellent electrochromic performance. The fast and large optical modulation synchronous as well as good energy storage makes the electrochromic device become a potential intelligent power supply. This morphology dependent electrochromic work provides a new vision for the construction of high-performance Zn2+- based electrochromic devices.

[EN] Organic-inorganic hybrid perovskite formamidinium lead triiodide NH2CHNH2PbI3 (FAPbI3), methylammonium lead triiodide CH3NH3PbI3 (MAPbI3) and formamidinium methylammonium lead triiodide (NH2CHNH2)1-x(CH3NH2)xPbI3 (FA1-xMAxPbI3) thin films were synthesized and deposited on indium tin oxide glass substrates by spin coating process. Thin films of mixed FA1-xMAxPbI3 (x = 0-1) perovskites obtained by mixing FAPbI3 and MAPbI3 in different proportions. The morphological, structural and optical proprieties of all synthetized perovskites have been analyzed as a function of the MA/FA ratio. X-ray diffraction analyses indicated the formation a cubic perovskite phase with space group Pm-3m in the composition range 0 ¿ x ¿ 1. Mixed perovskites FAMAPbI3 showed a high absorbance in the infrared region 780-900 nm. The band gap energy estimated from absorbance spectral measurements for FAMAPbI3 thin films ranges from 1.50 eV for FAPbI3 to 1.56 eV for MAPbI3, respectively. The overall PL emissions of mixed FA/MA perovskite thin films are located in intermediate values between 773 nm and 810 nm., This work was supported by Ministerio de Economia y Competitividad (ENE2013-46624-C4-4-R) and Generalitat valenciana (Prometeus 2014/044).

Au Pd bimetallic nanospheres were synthesized via a green approach based on an in situ seed-mediated growth method using Etlingera elatior (EE) leaf extract as a bioreducing and capping agent. The synthesized bimetallic Au1Pd1, Au1Pd10, Au10Pd1 and monometallic Au and Pd nanoparticles were characterized using various spectroscopic and microscopic techniques. This study reveals the morphology control of anisotropic Au nanoparticles, which can be achieved by the addition of palladium into the aqueous reaction mixture. Furthermore, the catalytic ability of each nanoparticle to catalyze the reduction of 4-nitrophenol to 4-aminophenol were investigated. The bimetallic nanoparticles are more efficient in catalyzing the reduction of 4-nitrophenol than monometallic Au and Pd whereby the Au1Pd1 was the most efficient, with a rate constant, k, of 24.0 × 10−3 min−1.

Preparation of poly[4-(5-oxy-1,3-dioxoisoindoline-2-yl)benzoyl] (PODB) crystals, which was an intractable aromatic poly(ester-imide), was examined by means of reaction-induced crystallization of oligomers during the polymerization. Highly crystalline PODB helical ribbons were obtained by the polymerization of N -(4-carboxyphenyl)-4-acetoxyphthalimide in aromatic solvent at 280–330 °C at a concentration of 0.5–1.0%. The PODB molecules aligned along the long axis of the helical ribbon. The pitch of the helix increased with the polymerization temperature and it could be controlled from 320 nm to 1.3 μm. Further, the fibrillar PODB crystals comprised of the helical and the non-helical blocks were prepared by the on-off switching of the helical morphology with the changing the temperature and the concentration of the polymerization. These results provided the methodology for the morphology control of polymer crystals.

The morphology of PbI 2 film plays a critical role in determining the quality of the resultant CH 3 NH 3 PbI 3 film and power conversion efficiency of CH 3 NH 3 PbI 3 perovskite solar cell. Here, we propose a solvent treatment method in the two-step sequential deposition process to control the morphology of PbI 2 film, which leads to enhanced power conversion efficiency. Hole transport material free perovskite solar cell is chosen as a paradigm to demonstrate this idea. Solvent (isopropanol, chlorobenzene, or ethanol) treated PbI 2 films exhibit dendrite-like or flake-like morphologies, which facilitate more complete conversion of PbI 2 to CH 3 NH 3 PbI 3 perovskite in ambient atmosphere with a relative high humidity. Therefore, enhanced performance is obtained with the solvent treated PbI 2 films. Average power conversion efficiency has been improved from 9.42% in the traditional two-step sequential deposition to 11.22% in solar cells derived from ethanol treated PbI 2 films.

Polypyrrole (PPy), as one of the conducting polymers, has emerged as a promising active material for high performance supercapacitor owing to its intrinsic characteristics ( e.g. high electrical conductivity and interesting redox properties). It’s attracting more and more attentions with the development of flexible/wearable devices thanks to the great flexibility and ductility of PPy as a polymer. This review presents a comprehensive understanding on synthesis, morphology control, electrochemical performances and solid-state devices of the nanostructured PPy and its nanocomposites. In the past decades, a variety of nanostructures, including one-, two-, and three-dimensional, have been designed and fabricated via different methods, demonstrating a great potential for the application as supercapacitor electrodes. Thereafter, many nanostructured PPy-based supercapacitors with different macroscopic configurations have been presented aiming to achieve better electrochemical performance, and some representative ones, for example, flexible and/or wearable supercapacitors, are summarized in this review. Cycling stability is another critical issue that determines its practicability of the PPy-based devices. Solutions to improve cycling performance and mechanisms behind are also discussed. Last, perspectives for the future development in nanostructured PPy-based supercapacitors are described. This review gives a summary of selected contributions which we hope to provide readers with a better understanding of the fast developing field of PPy-based supercapacitors.