Jason

Publication date: 1 March 2026

Source: Fuel, Volume 407, Part C

Author(s): Lifang Cao, Pu Wang, Yuhan Tang, Hong Liu, Jiasheng Wang

A major obstacle for bismuth peptides and proteins, in which Bi(III) is coordinated by three cysteine residues, is their kinetic lability when challenged with strong metal chelators. By simply replacing cysteines with selenocysteines, we significantly increased kinetic stability, extending the lifetime to several days. We further applied this strategy to a small protein containing six (seleno)cysteines, enabling coordination of two bismuth atoms.

Abstract

Bismuth peptides and proteins are emerging as versatile tools for medicinal chemistry and chemical biology. Bismuth(III) binds three cysteine residues in peptides and proteins with remarkable selectivity. While the thermodynamic stability of these bismuth complexes is outstanding, their kinetic lability imposes limitations. Introducing bismuth selenopeptides, we demonstrate that selenocysteine binds bismuth with substantially higher kinetic stability than cysteine. This effect was quantified by directly comparing a peptide containing three cysteine residues with an identical peptide containing three selenocysteines. Bismuth selenopeptides are not only inert to strong chelators such as ethylenediaminetetraacetic acid (EDTA) and diethylenetriaminepentaacetic acid (DTPA) but also to the natural metal-binding protein transferrin present in human plasma. We further demonstrate biological utility by developing bismuth selenopeptides that selectively bind and inhibit unrelated target proteins. To extend this concept to a more complex system, we investigated the human epidermal growth factor (EGF), a small protein comprising three disulfide bonds. We established that precisely two bismuth atoms bind to the six cysteine or selenocysteine residues in EGF and seleno-EGF, respectively. In the presence of EDTA, bismuth seleno-EGF remains fully intact, unlike its cysteine-based analog, consistent with observations from smaller peptides. Structural models confirm full preservation of the native EGF fold.

An enhanced stability 2D thermochromic perovskite (Tha₂MAPbI₄, TMPI, Tha = thiourea, MA = methylamine) smart window is developed. The TMPI exhibits a passive and intelligent optical regulation capability between a transparent and tinted state. Most importantly, the TMPI possesses significantly improved stability, low transition temperature, and short transition time, showing great potential for use in smart green buildings.

Abstract

Recently, there is rapid development of thermochromic metal halide perovskite (MHPs) for smart window applications due to their competitive optical performance and cost-effective synthesis. However, existing MHP smart windows predominantly feature 3D perovskite, which exhibits a deficiency in environmental stability, presenting persistent challenges for practical applications. This study introduces a novel and more durable 2D thermochromic perovskite, Tha₂MAPbI₄ (TMPI, Tha = thiourea, MA = methylamine), wherein Tha acts as a Lewis acid-base adduct. TMPI demonstrates a reversible transition, achieving 83.7% luminous transmittance in the cold state and 35.2% in the hot state, thereby showcasing a substantial solar modulation ability of 24.7%. Further analysis of the crystal structure reveals that the thermochromic behavior of TMPI arises from a phase transition between 0D perovskite and 2D perovskite, induced by a dehydration-hydration process. Notably, TMPI maintains thermochromic properties even after direct exposure to 75% relative humidity and 25 °C air for up to 28 days, a stark contrast to traditional 3D perovskites that lose their thermochromic capabilities within a few days under similar conditions. This research unveils TMPI as a thermochromic 2D perovskite that marks a significant advancement in environmental stability, indicating promising prospects for thermochromic smart windows.

Publication date: 15 May 2023

Source: Applied Catalysis B: Environmental, Volume 325

Author(s): Laís Reis Borges, Adriano H. Braga, Daniela Zanchet, Jean Marcel R. Gallo, José Maria C. Bueno

Nanocatalyst for Oxidative Desulfurization: Clean energy from fuel feedstocks is of paramount significance in the field of environmental science. MoO₃ nanoparticles presented influence on the reaction rate and selectivity in the oxidative desulfurization reaction of sulfides (ODS) while being very efficient. They showed an enhancement in the ODS process for the studied substrates under very mild conditions.

Abstract

Gathering clean energy from fuel feedstocks is of paramount significance in environmental science. In this area, desulfurization provides a valuable contribution by eliminating sulfur compounds from fuel feedstocks to ensure they can be used without emission of toxic sulfur oxides. MoO₃ nanoparticles have been hydrothermally synthesized and used as efficient catalyst in the oxidative desulfurization (ODS) of methylphenyl and diphenyl sulfide using TBHP or H₂O₂ as oxidant. The catalyst showed an enhancement in the ODS process of the two substrates revealing influence on the reaction rate and product selectivity. Temperature and solvent influenced the conversion for the desired product as well. The activity of the catalyst was stable for at least 3 continuous catalytic cycles. Catalytic performance of MoO₃ nanomaterial was comparable or better than other catalysts reported in the literature in terms of the sulfoxide or sulfone yield.

Publication date: 15 May 2022

Source: Applied Catalysis B: Environmental, Volume 305

Author(s): Jaeha Lee, Dongjae Shin, Eunwon Lee, Chengbin Li, Ji Man Kim, Jeong Woo Han, Do Heui Kim

A new method of inkjet printing-assisted melt processing is proposed for patterned growth of liquid crystalline thin films for high-performance organic field-effect transistor (OFET) arrays and integrated circuits. The OFET arrays exhibit uniform electrical properties with high average mobility of 6.31 cm² V⁻¹ s⁻¹. Further, inverter circuits with high gain and large static noise margins of 81.3% are achieved.

Abstract

Liquid crystalline (LC) organic semiconductors having long-range-ordered LC phases hold great application potential in organic field-effect transistors (OFETs). However, to meet real device application requirements, it is a prerequisite to precisely pattern the LC film at desired positions. Here, a facile method that combines the technique of inkjet printing and melt processing to fabricate patterned LC film for achieving high-performance organic integrated circuits is demonstrated. Inkjet printing controls the deposition locations of the LC materials, while the melt processing implements phase transition of the LC materials to form high-quality LC films with large grain sizes. This approach enables to achieve patterned growth of high-quality 2,7-dioctyl[1]-benzothieno[3,2-b][1]benzothiophene (C₈-BTBT) LC films. The patterned C₈-BTBT LC film-based 7 × 7 OFET array has 100% die yield and shows high average mobility of 6.31 cm² V⁻¹ s⁻¹, along with maximum mobility up to 9.33 cm² V⁻¹ s⁻¹. As a result, the inverters based on the patterned LC films reach a high gain up to 23.75 as well as an ultrahigh noise margin over 81.3%. Given the good generality of the patterning process and the high quality of the resulting films, the proposed method paves the way for high-performance organic integrated devices.

High‐oxidation CoO _x clusters substitutionally dispersed in the lattice of a rutile TiO₂ support (Co‐TiO₂) are obtained by a thermally induced phase segregation process and following O₂ plasma treatment; the strong interaction between CoO _x clusters and TiO₂ support induce the formation of CoTi cooperative catalytic centers, which enable the substantially improved intrinsic activity and stability of Co‐TiO₂ for oxygen evolution reaction.

Abstract

The development of economical, highly active, and robust electrocatalysts for oxygen evolution reaction (OER) is one of the major obstacles for producing affordable water splitting systems and metal‐air batteries. Herein, it is reported that the subnanometric CoO _x clusters with high oxidation state substitutionally dispersed in the lattice of rutile TiO₂ support (Co‐TiO₂) can be prepared by a thermally induced phase segregation process. Owing to the strong interaction of CoO _x clusters and TiO₂ support, Co‐TiO₂ exhibits both excellent intrinsic activity and durability for OER. The turnover frequency of Co‐TiO₂ is up to 3.250 s⁻¹ at overpotentials of 350 mV; this value is one of the highest in terms of OER performance among the current Co‐based active materials under similar testing conditions; moreover, the OER current density loss is only 6.5% at a constant overpotential of 400 mV for 30 000 s, which is superior to the benchmark Co₃O₄ and RuO₂ catalysts. Mechanism analysis demonstrates that charge transfer occurs between Co sites and their neighboring Ti atoms, triggering the efficient CoTi cooperative catalytic centers, in which OH* and O* are preferred to be adsorbed on the bridging sites of Co and Ti with favorable adsorption energy, inducing a lower energy barrier for O₂ generation.

Atomically dispersed and nitrogen coordinated iron (Fe‐N‐C) catalysts are prepared by using chemical vapor deposition. The catalysts exhibit outstanding oxygen‐reduction activity in acidic electrolytes, which can further transfer into membrane electrode assemblies (MEAs) for fuel cell applications. The MEAs are capable of generating current densities of 27 mA cm⁻² at 0.9 V (1.0 bar O₂) and 117 mA cm⁻² at 0.8 V (1.0 bar air).

Abstract

Atomically dispersed and nitrogen coordinated single metal sites (M‐N‐C, M=Fe, Co, Ni, Mn) are the popular platinum group‐metal (PGM)‐free catalysts for many electrochemical reactions. Traditional wet‐chemistry catalyst synthesis often requires complex procedures with unsatisfied reproducibility and scalability. Here, we report a facile chemical vapor deposition (CVD) strategy to synthesize the promising M‐N‐C catalysts. The deposition of gaseous 2‐methylimidazole onto M‐doped ZnO substrates, followed by an in situ thermal activation, effectively generated single metal sites well dispersed into porous carbon. In particular, an optimal CVD‐derived Fe‐N‐C catalyst exclusively contains atomically dispersed FeN₄ sites with increased Fe loading relative to other catalysts from wet‐chemistry synthesis. The catalyst exhibited outstanding oxygen‐reduction activity in acidic electrolytes, which was further studied in proton‐exchange membrane fuel cells with encouraging performance.

Magnetic sandwiches: What happens in a spin‐sandwiched layered magnet when the sandwiched spin is altered? Herein, this question was answered for two series of isostructural compounds by changing [MCp*₂]⁺ spins sandwiched between ferrimagnetic layers of [{Ru₂}₂(TCNQ)]⁻. The magnetic phase can be described as a competition between the interlayer magnetic interaction and the layer⋅⋅⋅[MCp*₂]⁺ interaction, which were tuned by solvation/desolvation and by changing M among Co, Fe, and Cr, respectively. Cp*=pentamethylcyclopentadienyl, TCNQ=7,7,8,8‐tetracyano‐p‐quinodimethane

Abstract

The insertion of “sandwiched spins” between magnetic layers could efficiently affect the interlayer magnetic correlations, but doing so increases the complexity in the interlayer spin alignment because of competition between the inserted spin‐layer interaction J _NNI and the interlayer through‐space interaction J _NNNI if the magnitude of J _NNI is of the same order as J _NNNI with reciprocal signs of the respective interactions. Herein, systematic tuning of the magnetic phase variations by J _NNI and J _NNNI in two kinds of metal‐variable isostructural series of supramolecular pillared layer magnets [MCp*₂][{Ru₂ ^II,II(2,3,5,6‐F₄CO₂)₄}₂(TCNQ)]⋅2 DCE (M=Co, Fe, Cr; 2,3,5,6‐F₄PhCO₂ ⁻=2,3,5,6‐tetrafluorobenzoate; TCNQ=7,7,8,8‐tetracyano‐p‐quinodimethane; DCE=1,2‐dichloroethane) and their DCE‐free series, in which [MCp*₂]⁺ (Cp*=η⁵‐C₅Me₅) species with S=0, 1/2, and 3/2 for M=Co, Fe, Cr, respectively, are sandwiched between ferrimagnetic layers of [{Ru₂}₂(TCNQ)]⁻, is demonstrated. The results showed that the flexible magnetic natures of these magnets are changeable in dependence on J _NNI and J _NNNI, as well as on interlayer inserted spins M.

Publication date: September 2020

Source: Journal of Catalysis, Volume 389

Author(s): Yongwoo Kim, Seung-hoon Kim, Hyung Chul Ham, Do Heui Kim

Pt, Cu, Fe, Ag, and Au metals incorporated with TiO₂ microspheres are used for the fabrication of light‐driven micromotors. These micromotors display different average velocities under UV light determined by their chemical potentials and catalytic properties toward the water splitting reaction.

Abstract

Catalytic light‐powered micromotors have become a major focus in current autonomous self‐propelled micromotors research. The attractiveness of such machines stems from the fact that these motors are “fuel‐free,” with their motion modulated by light irradiation. In order to study how different metals affect the velocities of metal/TiO₂ micromachines in the presence of UV irradiation in pure water, Pt/TiO₂, Cu/TiO₂, Fe/TiO₂, Ag/TiO₂, and Au/TiO₂ Janus micromotors are prepared. The metals have different chemical potentials and catalytic effects toward water splitting reaction, with both the effects expected to alter the photoelectrochemically‐induced reaction and propulsion rates. Analysis of structures, elemental compositions, motion patterns, velocities, and overall performances of different metals (Pt, Au, Ag, Fe, Cu) on TiO₂ are observed by scanning electron microscopy, energy dispersive X‐ray spectroscopy, and optical microscopy. Electrochemical Tafel analysis is performed for the different metal/TiO₂ structures and it is concluded that the effective velocity is a result of the synergistic effect of chemical potential and catalysis. It is found that the Pt/TiO₂ Janus micromotors exhibit the fastest motion compared to the rest of the prepared materials. Furthermore, after exposure to UV light, every fabricated micromotor shows high possibility of forming assembled chains which influence their velocity.

Controlled wettability: A series of Pd/SiO₂ with regulable wettability was synthesized using vinyl as the reductant and tested for the selective hydrogenation of styrene to ethylbenzene. The increased hydrophobicity enhanced the activity of the catalyst by decreasing the activation energy.

Abstract

The wettability had great influence on the catalytic performance of heterogeneous catalyst. In this manuscript, relationship between wettability and catalytic performance was studied by the preparation of Pd/SiO₂ with controllable wettability employing surface‐bonded vinyl as the reductant. The surface‐bonded vinyl ensured the reduction of PdCl₂ on the hydrophobic surface of SiO₂ to afford the hydrophobic Pd/SiO₂. The wettability of the catalysts could be adjusted by changing the content of phenyl on the surface. The catalysts were characterized by solid‐state CP/MAS NMR, TEM, HRTEM, XPS, XRD and ICP‐AES as well as water droplet contact angles. The catalysts showed zero‐order kinetics for the hydrogenation of styrene under mild conditions. The activation energy for this reaction was measured by the Arrhenius formula. The wettability was proved to influence the reaction activity by changing the activation energy. The increase in hydrophobicity led to higher activity by decreasing the activation energy for hydrogenation of styrene to ethylbenzene.

Publication date: September 2019

Source: Journal of Catalysis, Volume 377

Author(s): Weifeng Tu, Xinli Li, Renquan Wang, Haripal Singh Malhi, Jingyu Ran, Yanling Shi, Yi-Fan Han

Graphical abstract

Despite their captivating physicochemical properties, mesoporous silica nanoparticles are only supported as carriers. To enrich their performance, various metal species are encapsulated in their nanospaces for diverse functionalities. This review provides an overview highlighting the attractive features of these innovative constructs and a synopsis of the current advancements and latest breakthroughs in their potential catalytic and various biomedical applications.

Abstract

Despite their advantageous morphological attributes and attractive physicochemical properties, mesoporous silica nanoparticles (MSNs) are merely supported as carriers or vectors for a reason. Incorporating various metal species in the confined nanospaces of MSNs (M‐MSNs) significantly enriches their mesoporous architecture and diverse functionalities, bringing exciting potentials to this burgeoning field of research. These incorporated guest species offer enormous benefits to the MSN hosts concerning the reduction of their eventual size and the enhancement of their performance and stability, among other benefits. Substantially, the guest species act through contributing to reduced aggregation, augmented durability, ease of long‐term storage, and reduced toxicity, attributes that are of particular interest in diverse fields of biomedicine. In this review, the first aim is to discuss the current advancements and latest breakthroughs in the fabrication of M‐MSNs, emphasizing the pros and cons, the confinement of various metal species in the nanospaces of MSNs, and various factors influencing the encapsulation of metal species in MSNs. Further, an emphasis on potential applications of M‐MSNs in various fields, including in adsorption, catalysis, photoluminescence, and biomedicine, among others, along with a set of examples is provided. Finally, the advances in M‐MSNs with perspectives are summarized.

Publication date: September 2019

Source: Journal of Catalysis, Volume 377

Author(s): Cinthia R. Zanata, Cauê A. Martins, Érico Teixeira-Neto, Martha J. Giz, Giuseppe A. Camara

Graphical abstract

Publication date: 15 November 2019

Source: Applied Catalysis B: Environmental, Volume 257

Author(s): Huiyu Zhang, Shanhong Sui, Xianming Zheng, Ranran Cao, Pengyi Zhang

Abstract

Graphical abstract

Abstract

The ammonia synthesis from nitrogen and water under ambient conditions is one of the most inviting but challenging reaction routes. Although nitrogen is abundant in the atmosphere and the ammonia synthesis reaction is exothermic on the thermodynamics, the conversion of N₂ to ammonia is actually hard to proceed owing to the chemical inertness and stability of N₂ molecules. In industry, ammonia synthesis is carried out by the Haber-Bosch process under harsh conditions (300–500 °C, 20–30 MPa) associated with the requirement of substantial energy input and the enormous emission of greenhouse gases (e.g., CO₂). Recently, a growing number of studies on photo(electro)catalytic and electrocatalytic nitrogen reduction reaction (NRR) in aqueous solution have attracted extensive attention, which holds great promise for nitrogen fixation under room temperature and atmospheric pressure. However, the very low efficiency and ambiguous mechanism still remain as the major hurdles for the development of photochemical and electrochemical NRR systems. Here we provide an overview of the latest progresses, remaining challenges and future prospects in photocatalytic and electrocatalytic nitrogen fixation. Moreover, this review offers a helpful guidance for the reasonable design of photocatalysts and electrocatalysts towards NRR by combining theory predictions and experiment results. We hope this review can stimulate more research interests in the relatively understudied but highly promising research field of NRR.

Publication date: 5 October 2019

Source: Applied Catalysis B: Environmental, Volume 254

Author(s): Jifeng Pang, Junming Sun, Mingyuan Zheng, Houqian Li, Yong Wang, Tao Zhang

Abstract

Graphical abstract

The development of transition metal carbides synthesis and their application in biomass conversion in the aspects of (hemi)cellulose, lignin and platform chemicals conversion were highlighted and reviewed. The challenges and opportunities regarding the transition metal carbides and biomass conversion were also presented.