Over the last two decades, click chemistry and bioorthogonal chemistry have revolutionized the field of biomedical engineering. Extensive investigations have been conducted and allowed for unforeseeable developments in many different fields, including imaging, drug delivery, 3D cell culture, and bioprinting. The properties of advanced click and bioorthogonal chemical tools have now exceeded the expectations set by the researchers who first introduced the two concepts, calling for reevaluation. More importantly, their developments in distinct research contexts have led to conceptual divergences, which can now be a source of misunderstandings and disagreements. This perspective article aims to take a fresh look at the two concepts, with particular attention to their combination for applications in biological environments. After a short historical introduction, the definitions of click chemistry and bioorthogonal chemistry are revised, and the concept of ideal click chemistry is introduced. Chemical reactions that are commonly considered as click and bioorthogonal reactions are discussed in light of this new perspective. Finally, current challenges and new chemical concepts are presented, offering a new framework for future research.

2D–3D tin perovskites are considered as promising candidates for realizing efficient lead-free perovskite solar cells (PSCs). However, the ultrathin 2D phases could unfavorably affect charge transport and device performance. In the present work, we demonstrate that the introduction of D-homoserine lactone hydrochloride (D-HLH) can tailor the low-dimensional phases and improve the quality of 2D–3D tin perovskite films. The functional group in D-HLH can interact with FA+ and I– as well as Sn2+ in the precursor solution. These interactions not only affect the formation of tin perovskite film and favor the formation of thicker 2D phases but also decrease the defect density and suppress the nonradiative recombination. As a result, the efficiency of tin PSCs is significantly improved from 7.97 to 12.45%, and the stability of the device is also enhanced. This work provides a feasible strategy to regulate the low-dimensional phases in 2D–3D tin PSCs toward realizing high efficiency.

Semiconducting polymers have transport properties that can be tuned by both the synthetic design and processing techniques. Their thermopower, electronic conductivity, and low lattice thermal conductivity make them attractive in thermal management and thermoelectric applications, especially in form factors unfit for comparable inorganic ceramics. The effects of blending differing molecular weights and regioregularities of poly(3-hexylthiophene) (P3HT) on the thermal conductivity of films of P3HT doped with 2,3,5,6-tetrafluoro-7,7,8,8-tetracyanoquinodimethane were investigated in order to develop design rules for the co-optimization of thermal and electronic properties. The thermal conductivity of blended P3HT films at room temperature was found to be controlled by the distribution of molecular weights and regioregularities of chains. The resulting thermal conductivity of P3HT at room temperature was found to span 0.2–0.85 W/mK without specialized processing methods. Upon electrical doping, a significant decrease in thermal conductivity was found at all blending compositions despite each composition having a comparable electronic conductivity. These results suggest the blending of molecular weights and regioregularities as a rational means to optimize thermal conductivity while maintaining desired electronic properties in semiconducting polymers.

Carbon nanomaterials have shown attractive application prospects for efficient electrocatalysis for two-electron oxygen reduction reaction (2e– ORR) toward hydrogen peroxide (H2O2) electroproduction. By synthesizing sulfur-doped defective nanocarbons (S-DNC) through direct pyrolysis in the presence of sulfur, utilizing fullerene (C60) as the precursor, we achieved promising results. The as-obtained S-DNC catalyst demonstrated a high ORR onset potential of 0.78 V and high selectivity toward the 2e– pathway (∼90%). Importantly, when used as the cathode catalyst in a H cell, the S-DNC electrode exhibited impressive features such as a high H2O2 yield rate (690 mg L–1 h–1), quantitative faradic efficiency (∼100%), and rapid organic pollutant degradation rate. Theoretical calculations revealed that the combination of pentagon defects and sulfur dopants synergistically promoted the activation of the O2 molecule and facilitated the desorption of oxygen intermediates. This discovery significantly contributes to the understanding and advancement of carbon-based catalysts for efficient electroproduction of H2O2 by incorporating heteroatom dopants and topological pentagon defects synergistically.

Attempts to develop an efficient wound dressing have come to the forefront in the field of wound healing. Herein, we employ a microfluidic electrospray device to prepare the novel multifunctional discal microparticles (DMPs) with therapeutics encapsulation for wound healing. The DMPs are derived from the deformation of droplets containing κ-carrageenan and methacrylate-esterified hyaluronic acid. These DMPs possess highly porous structures due to the cross-linking and lyophilization of their hybrid hydrogels. Benefiting from the special discal morphology and porous structures, the DMPs offer candidates to wound dressing with large contact area and excellent drug release ability. By loading vascular endothelial growth factors and antimicrobial peptides, the resultant DMPs were imparted with good biocompatibility, sterilization, and angiogenesis in vitro. We have demonstrated that, in the skin defect model of Sjögren’s syndrome mice, the multifunctional DMPs treated acute wounds could perform accelerated tissue regeneration and remodeling, down-regulated inflammatory response, and promoted angiogenesis in vivo. These results indicated that our proposed DMPs have great potential to serve as a satisfactory dressing for promoting wound healing.

The diamagnetism of graphene restricts its suitability as a candidate material for future spintronic applications. In this study, we unveil the inherent ferromagnetism by deliberately incorporating zigzag beryllium chains into the structure of graphene. Using swarm-intelligence structure search methods and first-principles calculations, we have predicted a global minimum BeC5 monolayer, demonstrating an intrinsic magnetic moment of 0.65 μB per unit cell. Notably, the BeC5 monolayer exhibits a node-line-like characteristic at the Fermi level, giving rise to a high density of states and a pronounced Van Hove singularity. The distinct electronic structure activates Stoner’s criterion, resulting in the onset of ferromagnetic instability in BeC5. Monte Carlo simulations utilizing the Ising model indicate a Curie temperature of 80 K for BeC5. Our study illustrates the sensitivity of ferromagnetic instability to biaxial tensile strain, with the transition from ferromagnetism to nonmagnetism taking place at a critical strain of 4.6%. This transition is accompanied by the emergence of Dirac states within the system.

Efficient separation of physicochemically similar alkanes is of vital importance. Adsorptive separation utilizing porous materials such as metal–organic frameworks with tunable pore structure and surface functionality represents an energy-efficient technology. In this study, we demonstrate successful separation of alkanes with varying degree of branching using a microporous nickel isonicotinate framework, Ni(4-PyC)2. Its 2-fold interpenetrated diamondoid structure with well-suited pore size enables selective adsorption of linear and monobranched hexane isomers, while excluding dibranched isomer. Breakthrough experiments validated its capability to completely discriminate all three hexane isomers. Ab initio calculations combined with in situ infrared spectroscopic analysis unveiled the nature of host–guest interactions and differences in the binding energies and diffusion barriers among the isomers. Having well-balanced adsorption uptakes (146 and 79 mg g–1 of nHEX and 3MP), high nHEX/DMB uptake ratio (12.2) and fast kinetics, Ni(4-PyC)2 stands out as a promising adsorbent for complete separation of hexane isomers under ambient conditions.

Electrically conductive metal–organic frameworks (EC-MOFs) are highly sought-after materials for electrocatalysis and energy storage because of their unique combination of intrinsic porosity and electrical conductivity. However, it is challenging to incorporate these exciting materials into functional devices because of the difficulty in synthesizing the frameworks directly on desired substrates and at a scale suitable for mass distribution with a controlled morphology. Electrosynthesis can provide a means that is both scalable and synthetically controllable by which metal–organic frameworks can be grown directly on targeted substrates for use in electronic devices. In this work, we demonstrate the electrosynthesis of an EC-MOF constructed with nickel and 2,3,6,7,10,11-hexahydroxytriphenylene, namely Ni-HHTP, with distinct disc and flower-like morphologies (Ni-HHTP-Disc and Ni-HHTP-Flower) by varying the ligand concentrations. The electrochemical performance of Ni-HHTP-Flower greatly exceeds that of bulk Ni-HHTP, boasting gravimetric capacitances and electrochemically active surface areas up to 10 times that of the bulk material because of mesoporous features absent in the bulk, showcasing electrosynthesis as a promising method for preparing future EC-MOF-based devices.

Propane (C3H8) is a widely used fuel gas. Metal–organic framework (MOF) physisorbents that are C3H8 selective offer the potential to significantly reduce the energy footprint for capturing C3H8 from natural gas, where C3H8 is typically present as a minor component. Here we report the C3H8 recovery performance of a previously unreported lonsdaleite, lon, topology MOF, a chiral metal–organic material, [Ni(S-IEDC)(bipy)(SCN)]n, CMOM-7. CMOM-7 was prepared from three low-cost precursors: Ni(SCN)2, S-indoline-2-carboxylic acid (S-IDECH), and 4,4′-bipyridine (bipy), and its structure was determined by single crystal X-ray crystallography. Pure gas adsorption isotherms revealed that CMOM-7 exhibited high C3H8 uptake (2.71 mmol g–1) at 0.05 bar, an indication of a higher affinity for C3H8 than both C2H6 and CH4. Dynamic column breakthrough experiments afforded high purity C3H8 capture from a gas mixture comprising C3H8/C2H6/CH4 (v/v/v = 5/10/85). Despite the dilute C3H8 stream, CMOM-7 registered a high dynamic uptake of C3H8 and a breakthrough time difference between C3H8 and C2H6 of 79.5 min g–1, superior to those of previous MOF physisorbents studied under the same flow rate. Analysis of crystallographic data and Grand Canonical Monte Carlo simulations provides insight into the two C3H8 binding sites in CMOM-7, both of which are driven by C–H···π and hydrogen bonding interactions.

Oxygen vacancy (VO) is a fundamental and intrinsic defect in metal oxides since its formation is subject to various growth and annealing processes and it significantly affects the material properties. Therefore, the formation energy of an oxygen vacancy is of great interest in the fabrication and investigation of metal oxides. Traditional methods for obtaining the formation energy of an oxygen vacancy such as theoretical calculation and experiment require expensive costs, making it difficult to explore a large number of metal oxides. Here, machine learning (ML) models are built for rapid prediction of the formation energy of an oxygen vacancy. We show that an ensemble of multiple ML models allows the prediction of the formation energy of an oxygen vacancy in a wide regime of an unexplored latent chemical space from binary to quinary oxides.