Room-temperature Preparation Research Articles

H2O2-assisted room temperature preparation of crystalline TiO2 and Ti3C2Tx-derived C-doped amorphous TiOx homojunction for photocatalytic degradation of tetracycline

The light absorption, active sites, and charge carriers separation of photocatalysts are extremely important factors in the field of photocatalysis. Near-perfect lattice-matched homojunction constructed using disorder engineering and doping strategies is an effective strategy to improve photocatalytic activity. Herein, we developed crystalline TiO2 nanoparticles (NPs) and Ti3C2Tx MXene-derived C-doped amorphous TiOx homojunction (TCT) at room temperature. In this homojunction, TiO2 NPs are evenly distributed on the surface of the C-TiOx nanosheet to form a type-II structure, which promotes the separation of photogenerated carriers. The light absorption range of TCT extends to 550 nm due to the presence of intermediate energy levels in C-TiOx, which increases its photon absorption capacity. Moreover, TCT possesses a large number of oxygen vacancies, which are beneficial for improving the adsorption and degradation of pollutants. These characteristics of TCT could significantly improve its photodegradation performance for tetracycline. Interestingly, the precursor mass ratio of TCT with the best degradation efficiency is different under different illumination conditions, which is attributed to the different band gaps of C-TiOx and TiO2 NPs resulting in different light absorption ranges. This work provides a new approach to rationally designing crystalline and amorphous homojunction for photocatalytic applications.

Enhanced degradation of E2/EE2 by BiPO4/AgI/BC composite photocatalysts via BC-enhanced ·O2-

This study presents the synthesis of highly active BiPO4/AgI/BC composite photocatalysts via a green, simple, and low-cost ambient temperature precipitation method. The electron transfer rate and visible-light responsiveness can be effectively enhanced by utilizing BiPO4 compounded with the semiconductor AgI, which has a narrow bandgap and good visible-light responsiveness. Additionally, the introduction of biocarbon (BC) enhances the absorption and separation of photogenerated electrons and holes under visible light. Notably, the synthesized BP-AgI0.6-BC5 % could remove 99.16 % and 99.7 % of EE2 and E2, respectively, at a concentration of 3 mg/L after 40 min of light exposure. The capture experiments and electron paramagnetic resonance spectroscopy reveal that the main active substance in the system is ·O2-, with BC playing a crucial role in enhancing the ·O2- concentration in the system. The findings from phytotoxicity and antimicrobial tests reveal that BP-AgI0.6-BC5 % can efficiently degrade pollutants, producing degradation products that are substantially less toxic than the original pollutants. Moreover, it can remove more than 99.99 % of E. coli under both dark and light conditions, demonstrating excellent antimicrobial performance. Additionally, the photocatalytic mechanism and degradation pathway were examined in this study. Notably, the composite photocatalysts synthesized in this study achieved efficient degradation of EE2 and E2 under visible light conditions while exhibiting efficient bactericidal function. Furthermore, the room-temperature preparation method is conducive to industrial-scale production, highlighting a better prospect for practical applications.

Room temperature preparation of novel g-C3N4/RuNP/ZIF-8 Z-scheme heterojunction for solar-light driven H2 generation

We present a novel approach for the room temperature synthesis and integration of Ru nanoparticles into a Z-scheme heterojunction comprising graphitic carbon nitride (CN) and zeolitic imidazolate framework-8 (ZIF-8). This heterojunction demonstrates outstanding efficiency in sunlight-driven hydrogen (H2) generation via water splitting. Various structural and spectroscopic analyses elucidate Ru nanoparticles' successful incorporation and synergistic effects within the CN/ZIF-8 heterojunction because the decrease in interplanar spacing due to π-π stacking interactions between aromatic rings of tri-s-triazine in CN and imidazole rings in ZIF-8. The Z-scheme configuration facilitates efficient charge separation and promotes H2 production. Additionally, Ru nanoparticles offer alternative electron transfer pathways, enhancing carrier separation and prolonging the lifespan of photoinduced charges compared to CN and ZIF-8 alone. Notably, RZCN-2 heterojunction exhibited significantly enhanced hydrogen production, reaching 5245 μmol g−1 h−1. By analyzing work functions and energy band structures, we demonstrate that the strong interfacial electric fields across the Z-scheme heterojunction effectively mitigate the recombination of photogenerated charges while maintaining the necessary redox capacity for efficient H2 production. The room temperature synthesis and integration of Ru nanoparticles provide a practical and effective strategy for optimizing photocatalytic activity and promoting sustainable energy conversion, thereby advancing photocatalytic technologies.

A Room-Temperature Strategy to Synthesize Ce/Tb-Codoped NaYF4 Nanoparticles with a Photoluminescence Quantum Yield Exceeding 50.

NaYF4:Ce3+,Tb3+ down-conversion nanoparticles with a photoluminescence quantum yield (PLQY) of 54.8% are synthesized by using a ligand-assisted coprecipitation method in this study. The reaction is completed within 1 min at room temperature, and short-chain hexanoic acid and hexylamine serve as the binary ligands, which enable us to synthesize highly luminescent NaYF4:Ce3+,Tb3+ nanoparticles at room temperature. X-ray diffraction (XRD) and transmission electron microscopy (TEM) are used to characterize the as-prepared nanocrystals. The results reveal that the NaYF4:Ce3+,Tb3+ nanocrystals exhibit excellent dispersion and have a particle size of 2.7 nm. Our NaYF4:Ce3+,Tb3+ nanocrystals possess the advantages of room-temperature preparation, high PLQY, and ultrasmall particle size. These results reveal that the NaYF4:Ce3+,Tb3+ nanocrystals might have a high potential in the applications of lighting, display devices, and bioimaging.

High‐Performance Nd: AIZO/Al2O3 Dual Active Layer Design Without Thermal Annealing: High‐Speed Electron Transport and Defect Modification in Thin Film Transistors

Flexible wearable electronics have been developing rapidly in recent years, and one of its core devices, thin‐film transistor (TFT), is also attracting attention. Current TFT preparation processes usually require high annealing temperatures (>350 °C), which is not conducive to their application on most flexible substrates (PET, PEN, nanopaper, etc.). In this article, a strategy for the room temperature preparation of Nd:AIZO/Al2O3 dual‐layer TFT devices is proposed, which has appreciable electrical properties without additional annealing treatment. Taguchi orthogonal experimental methods are used to investigate the effects of three essential process parameters on the performance of the films and devices. As Nd:AIZO deposition time decreases and Al2O3 oxygen percentage and time during deposition increase, the μsat and SS of TFT devices are improved. With the preferred combination of parameters applied to the device preparation, the device exhibits a saturation mobility μsat of 24.3 cm2 V−1 s−1, a threshold voltage Vth of −1.4 V, a subthreshold swing SS of 0.21 V decade−1 and an Ion/Ioff ratio of 4.26 × 108. The ultra‐thin Al2O3 layer act as defect modification and form high‐speed electron transport in channel layer. The room temperature preparation of the dual‐layer TFT process proposed in this article is compatible with large‐size low‐cost flexible substrates. It has great potential for application in green flexible wearable electronics.

Robust and Transparent Silver Oxide Coating Fabricated at Room Temperature Kills Clostridioides difficile Spores, MRSA, and Pseudomonas aeruginosa.

Antimicrobial coatings can inhibit the transmission of infectious diseases when they provide a quick kill that is achieved long after the coating application. Here, we describe the fabrication and testing of a glass coating containing Ag2O microparticles that was prepared from sodium silicate at room temperature. The half-lives of both methicillin-resistant Staphylococcus aureus (MRSA) and Pseudomonas aeruginosa on this coating are only 2-4 min. The half-life of Clostridioides difficile spores is about 9-12 min, which is extremely short for a spore. Additional tests on MRSA demonstrate that the coating retains its antimicrobial activity after abrasion and that an increased loading of Ag2O leads to a shorter half-life. This coating combines the properties of optical transparency, robustness, fast kill, and room temperature preparation that are highly desirable for an antimicrobial coating.

Scalable and room-temperature preparation of Cs2HfCl6 double perovskites with recorded photoluminescence efficiency and robust stability

Vacancy-ordered double perovskites (DPs) are promising candidates for modern white light-emitting-diodes (WLEDs) due to their low toxicity and unique optical properties. However, the grand challenge is that DPs synthesized at room temperature (RT) typically have a low photoluminescence quantum yield (PLQY), most of which reported below 51 %, making them impractical for applications. Here, we present a facile strategy for the mass production of Bi3+ and Te4+ co-doped Cs2HfCl6 (CHC) DPs at RT, to realize single-component dual-band emission with a high color rendering index. It is witnessed that the rationally designed ligand [Hmim]Cl facilitates a strong chemical interaction between the ligand and DPs. This interaction allows [Hmim]Cl to coordinate with undercoordinated Hf4+ ions and provide excess chloride ions to the surface of the DPs. Consequently, it effectively controls the crystallization of DPs, protects them against moisture, reduces surface defects, and increases the migration barrier of halogen ions. As a result, the DPs exhibit excellent overall performance with robust photostability and a superior PLQY of 96.4 %, which is ∼ 2 times the highest reported value for similar DPs synthesized at RT. Current work presents a potential pathway for the mass production of high-quality DPs under mild conditions, leading to the development of signal-component WLEDs.

Room-Temperature Preparation of Platinized Nonstoichiometric Tungsten Oxide via Platinum Photodeposition Followed by Chemical Reduction: Kinetic Enhancement of Photocatalytic Oxidation and Disinfection under Low-Intensity Visible-Light Irradiation

Room-Temperature Preparation of Platinized Nonstoichiometric Tungsten Oxide via Platinum Photodeposition Followed by Chemical Reduction: Kinetic Enhancement of Photocatalytic Oxidation and Disinfection under Low-Intensity Visible-Light Irradiation

Chemoselective electrochemical seleno-cyclization of dienes to medium-sized benzo[b]azocines

The preparation of medium-sized benzo[b]azocines has always been challenging because of inherently unfavorable enthalpy and entropy factors. This report presents a novel approach for accessing 8-membered seleno-benzo[b]azocines via electrochemically-driven seleno-cyclization. This method enables room-temperature preparation of various structurally diverse medium-sized seleno-benzo[b]azocines. The facile deselenation of the seleno-cyclization products to generate functionalized dienes is an additional benefit of this indispensable reaction. Mechanistic insights are presented based on radical inhibition experiments and cyclic voltammetry measurements, which elucidate the radical pathway. Finally, density functional theory calculations further rationalize the rate-determining step and the unique chemoselectivity observed in this transformation.

Room-Temperature Synthesis of Tubular Hexagonal Boron Nitride under Pressure

Hexagonal boron nitride (h-BN) exhibits interesting optical and mechanical properties, including chemical and thermal stability. Extensive techniques have been applied for the realization of h-BN at high temperatures. Here, we propose a room-temperature preparation of h-BN at high pressure through the compression of ammonium azide and boron powder. The structure and morphology of the obtained h-BN are found to possess tubular-like features, and the selected-area electron diffraction and electron energy-loss spectroscopy support the formation of h-BN. Remarkably, h-BN grows gradually from the surface of boron particles to form a core–shell structure. This tubular morphology of h-BN with a size of 70 nanometers in length and 27 nanometers in width differs from the conventional lamellar h-BN generated with temperature assistance. Our results demonstrate a method for the room-temperature synthesis of tubular h-BN, which shows great promise for the preparation of other nitrides at high pressure and room temperature.

Room-temperature assembled 3D macro-porous Ti3C2Tx/RGO hybrid hydrogel and the application as the self-standing electrode for sodium-ion storage

Assembling two-dimensional (2D) MXene nanosheets into monolithic three-dimensional (3D) structures is an efficient pathway to transfer the nanoscale properties to practical applications. Nevertheless, the majority of the preparation schemes described in the literature are carried out at relatively high temperatures, which inevitably leads to the notorious high-temperature oxidation issue of MXenes. Preparing MXene-based hydrogels at lower temperatures or even room temperature is of great research importance. In this study, we report a novel and efficient room-temperature gelation method for fabricating 3D macro-porous Ti3C2Tx MXene/reduced graphene oxide (RGO) hybrid hydrogels, using anhydrous sodium sulfide (Na2S) as the primary reducing agent and l-cysteine as the auxiliary crosslinker. This room-temperature preparation technique successfully prevents the oxidation issue of MXenes and generates porous aerogels with excellent structural robustness after freeze-drying. As the self-standing anode for sodium-ion storage, the optimized 3D Ti3C2Tx MXene/RGO electrode possesses a specific capacity of 152 mAh/g at 0.1 A/g and good cycling stability with no significant capacity degradation after 500 cycles, which is significantly higher than that of the vacuum-filtered MXene film. This work demonstrates a straightforward room-temperature gelation method for constructing 3D MXene-based hydrogels to avoid the oxidation of MXenes, and casts new insight on the mechanism of the graphene oxide (GO)-assisted gelation.

Room-Temperature Synthesis of Carbon Dot/TiO2 Composites with High Photocatalytic Activity

Benefiting from the wide-range absorption and adjustable energy gap, carbon dots (C-dots) have attracted a great deal of attention and they have been used to sensitize semiconductor nanocomposites to boost the efficiency of energy conversion devices, while there is still a lack of fundamental understanding of the interaction between such materials and their influence on the catalytic activity on the reaction process. In this study, C-dots were used to modify TiO2 to form a direct Z-scheme (DZS) junction for enhancement of the photocatalytic activity. The C-dot/TiO2 composite was prepared by ultrasonication at room temperature through coupling between the Ti-O-C bond and electrostatic interaction. The C-dots can dramatically enhance the absorption of the composite by forming the DZS, and the composite is enabled to generate more free radicals, which facilitate ∼10 times higher photocatalytic activity compared to that of TiO2. As a proof of concept, the as-prepared C-dot/TiO2 was used for textile wastewater dye degradation. This study provides an efficient approach for room-temperature preparation of C-dot/TiO2 composites with high photocatalytic activity.

A Facile Molecular Approach to Amorphous Nickel Pnictides and Their Reconstruction to Crystalline Potassium-Intercalated γ-NiOOHx Enabling High-Performance Electrocatalytic Water Oxidation and Selective Oxidation of 5-Hydroxymethylfurfural.

The low-temperature molecular precursor approach can be beneficial to conventional solid-state methods, which require high temperatures and lead to relatively large crystalline particles. Herein, a novel, single-step, room-temperature preparation of amorphous nickel pnictide(NiE; EP, As) nanomaterials is reported, starting from NaOCE(dioxane)n and NiBr2 (thf)1.5 . During application for the oxygen evolution reaction (OER), the pnictide anions leach, and both materials fully reconstruct into nickel(III/IV) oxide phases (similar to γ-NiOOH) comprising edge-sharing (NiO6 ) layers with intercalated potassium ions and a d-spacing of 7.27Å. Remarkably, the intercalated γ-NiOOHx phases are nanocrystalline, unlike the amorphous nickel pnictide precatalysts. This unconventionalreconstruction is fast and complete, whichisascribed to the amorphous nature of the nanostructured NiE precatalysts. The obtained γ-NiOOHx can effectively catalyse the OERfor 100 h at a high current density (400 mAcm-2 ) and achieves outstandingly high current densities (>600 mAcm-2 ) for the selective, value-added oxidation of 5-hydroxymethylfurfural (HMF). The NiP-derived γ-NiOOHx shows a higher activity for both processes due to more available active sites.It is anticipated that the herein developed, effective, room-temperature molecular synthesis of amorphous nickel pnictide nanomaterials can be applied to other functional transition-metal pnictides.

Novel polyamide/silica/chitosan covalent hybrid: One-step BIC/sol-gel preparation at room temperature and dual applications in Hg2+ electrochemical probing and dye adsorption

Room-temperature preparation of polymer-based covalent hybrids, which with multiple functional characteristics, is instrumental to overcome the performance shortcomings of single-polymer materials and broaden their applications thus. Herein, by introducing chitosan (CS) as a starting substrate into benzoxazine-isocyanide chemistry (BIC)/sol-gel reaction system, a novel polyamide (PA)/SiO2/CS covalent hybrid (PA-Si-CS) was successfully prepared in-situ at 30 °C. PA-Si-CS's chemical structure and elementary properties were characterized here. The introduction of CS combining with the presence of diverse N, O-containing segments (amide, phenol -OH, Si-OH, etc.) in PA-Si-CS provided its synergistic adsorption for Hg2+ and anionic dye Congo red (CR). The capture of PA-Si-CS for Hg2+ was rationally applied to the “enrichment”-type electrochemical probing of Hg2+. Relevant detection range, detection limit, interference, and probing mechanism were systematically analyzed. Compared with the experimental results of control electrodes, the electrode modified with PA-Si-CS (PA-Si-CS/GCE) showed a significantly enhanced electrochemical response to Hg2+, with a detection limit up to ~2.2 × 10−8 mol/L. In addition, PA-Si-CS also exhibited the specific adsorption for CR. Systematic analyses of dye adsorption selectivity, kinetics, isothermal models, thermodynamics, and adsorption mechanism told that PA-Si-CS can be used as an efficient CR adsorbent, with a maximum adsorption capacity of ~348 mg/g.

Preparation of Zr-based amorphous composites strengthened by three-dimensional continuous copper mesh and its mechanical property

Bulk amorphous alloys appear as promising candidate materials with a wide range of applications in implants. However, their brittleness at room temperature and small preparation size are two key problems restricting them in practical application. In this study, the atomized Zr48Cu47.5Al4Co0.5 (ZCAC) amorphous powders were coated with a layer of copper (Cu) by chemical plating method, and then the Cu coated amorphous powders were sintered to prepare Cu/ZCAC composites by using sparking plasma sintering (SPS) technology. The results show that relative density of the composites was slightly promoted with the increase of Cu content. The compression strength of the composite with 10.1 vol% Cu was 1531 MPa with poor plasticity. While the Cu content increased to 31.2 vol%, the strength of the composite dropped to 1209 MPa with a fracture strain of 9.8 %, which followed the mixture rule according to theoretical calculation.

A MOF-derived porous In2O3 flower-like hierarchical architecture sensor: near room-temperature preparation and fast trimethylamine sensing performance

A MOF-derived porous In2O3 flower-like hierarchical architecture sensor is prepared at near room temperature, which exhibits a high response and a fast response speed towards trimethylamine.

One-Step Synergistic Treatment Approach for High Performance Amorphous InGaZnO Thin-Film Transistors Fabricated at Room Temperature.

Amorphous InGaZnO (a-InGaZnO) is currently the most prominent oxide semiconductor complement to low-temperature polysilicon for thin-film transistor (TFT) applications in next-generation displays. However, balancing the transmission performance and low-temperature deposition is the primary obstacle in the application of a-InGaZnO TFTs in the field of ultra-high resolution optoelectronic display. Here, we report that a-InGaZnO:O TFT prepared at room temperature has high transport performance, manipulating oxygen vacancy (VO) defects through an oxygen-doped a-InGaZnO framework. The main electrical properties of a-InGaZnO:O TFTs included high field-effect mobility (µFE) of 28 cm2/V s, a threshold voltage (Vth) of 0.9 V, a subthreshold swing (SS) of 0.9 V/dec, and a current switching ratio (Ion/Ioff) of 107; significant improvements over a-InGaZnO TFTs without oxygen plasma. A possible reason for this is that appropriate oxygen plasma treatment and room temperature preparation technology jointly play a role in improving the electrical performance of a-InGaZnO TFTs, which could not only increase carrier concentration, but also reduce the channel-layer surface defects and interface trap density of a-InGaZnO TFTs. These provides a powerful way to synergistically boost the transport performance of oxide TFTs fabricated at room temperature.

Improving the performance of perovskite solar cells via TiO2 electron transport layer prepared by direct current pulsed magnetron sputtering

Organic-inorganic hybrid metal halide perovskite solar cells (PSCs) with planar heterojunction structures were fabricated. The traditional methylammonium lead iodide (CH3NH3PbI3, MAPbI3) was selected as the photovoltaic convert layer. The TiO2 electron transport layer (ETL) was prepared by the sol-gel and direct current pulsed magnetron sputtering (DC-PMS) technologies. PSCs with Sol-gel and DC-PMS TiO2 ETLs showed power conversion efficiencies of 13.4% and 16.1%, respectively. The detailed measurement results showed that the DC-PMS TiO2 ETL contained high-density chain-like structures, which consisted of nanosized anatase TiO2 nuclei. Compared with the short-circuit current of 20.08 mA/cm2 for PSCs with Sol-gel TiO2 ETL, the chain-like structure in the DC-PMS TiO2 ETL could effectively improve the short-circuit current to 22.11 mA/cm2. In addition, compared with the hysteresis index of 38.5% for PSCs with Sol-gel TiO2 ETL, the chain-like structure and higher surface potential of the DC-PMS TiO2 ETL could effectively reduce the hysteresis index to 14.9%. Finally, because of the whole room temperature preparation process, DC-PMS technology is an ideal candidate for flexible application of PSCs, which could be applied to the organic substrate without resistance to high temperature.

Room Temperature Preparation of Two-Dimensional Black Phosphorus@Metal Organic Framework Heterojunctions and Their Efficient Overall Water-Splitting Electrocatalytic Reactions.

Black phosphorus/two-dimensional (2D) metal-organic framework (BP@MOF) heterojunctions were synthesized via templated growth of 2D MOF-Fe/Co nanoplatelets on the surface of exfoliated BP nanosheets at room temperature. Because Fe3+ and Co2+ ions were absorbed onto the BP surface through coordination with the lone pair electrons of 2D BP, the BP@MOF heterojunction had an intimate interface with strong interactions. Electrochemical oxygen and hydrogen evolution reactions were studied using BP@MOF as the electrocatalyst. High activity of the overall water splitting in 1.0 M KOH was observed under a current density of 10 mA cm-2. The corresponding overpotentials for HER and OER were as low as 180 and 246 mV, respectively. Meanwhile, the BP@MOF exhibited good environmental stability and long-term electrocatalytic activity for OER and HER, owing to the encapsulation of BP nanosheets by the 2D MOF-Fe/Co. Through this study, a unique hybrid 2D nanomaterial is discovered for the efficient electrolytic splitting of water.

Near-unity photoluminescence quantum yield Mn-doped two-dimensional halide perovskite platelets via hydrobromic acid-assisted synthesis

Although two-dimensional lead halide based perovskite has been developed for nearly five years, the room temperature preparation for achieving high efficiency Mn2+ emission in the lead halide perovskites is still facing huge challenges. Herein, we studied photoluminescent properties of highly emitting Mn2+ ions doped PEA2PbBr4 perovskite platelets synthesized at room temperature by a facile hydrobromic acid-assisted (HBr-assisted) solid-liquid mixing strategy. The Mn-doped platelets with different Mn doping levels were synthesized by controlling Mn/Pb molar feed ratio and HBr addition volume. The photoluminescence (PL) quantum yield (QY) of orange-color (605 nm) of Mn-doped platelets reached 98%. Their optical properties were studied by steady-state and time-resolved PL spectroscopy. The temperature-dependent PL spectra revealed that the improvement mechanism of Mn luminescence and thermal stability was related to the reduction of the nonradiative defect/trap states through the HBr-induced surface passivation and enhancement of the exciton-to-Mn2+ energy transfer. This work provides a facile HBr solution-assisted method for preparing high-quality 2D Mn-doped perovskite platelets with stable and efficient luminescence.