Small science 

About: Small science is an academic journal published by Wiley. The journal publishes majorly in the area(s): Chemistry & Computer science. It has an ISSN identifier of 2688-4046. It is also open access. Over the lifetime, 122 publications have been published receiving 499 citations.

Carbon Dots in Bioimaging, Biosensing and Therapeutics: A Comprehensive Review

Abstract: Carbon dots (CDs), comprising crystalline graphitized carbon cores and polymer surface groups, are currently attracting a lot of interest in biological fields owing to their fluorescent properties, high photostability, biocompatibility and low toxicity. In addition, the easy preparation and functionalization of CDs stimulate the development of CDs‐based composite materials with specific functions. Presently, the biological applications of CDs are growing at a remarkable speed, justifying the need for up‐to‐date review articles that capture recent progress in this blossoming field. In this review, breakthroughs in the synthesis, modification, optical properties, toxicology and biocatalytic platforms of CDs are described. Further, recent research related to bioimaging, biosensing, drug delivery, antibacterial, anticancer (photothermal therapy, photodynamic therapy and synergistic therapy) and antiviral therapies involving CDs are discussed in detail. Finally, a perspective on the prospects and challenges of CDs in the fields of biomedicine and biotechnology is provided.

Recent Progress on Semiconductor Heterojunction‐Based Photoanodes for Photoelectrochemical Water Splitting

Abstract: For photoelectrochemical (PEC) water splitting, the utilization of semiconductor heterojunctions as building blocks for photoanodes allows for high light absorption, effective charge separation, and superior redox capability, greatly boosting the solar energy conversion efficiency. This review mainly focuses on the construction of heterojunction photoanodes, improvement strategies of carrier transmission, and their application in PEC water splitting. First, a series of carrier dynamics characterization methods are introduced to reveal the principle and significance of promoting carrier transport in heterojunctions. Then, from the perspective of the mechanism of promoting the separation and transport of charge carriers, several strategies are summarized and analyzed, including the micro/nanostructure, energy band structure, photothermal effect, piezoelectric effect, pyroelectric effect, ferroelectric effect, and intermediate layer. Finally, the challenges and opportunities for heterojunction photoanodes in PEC reactions are explained clearly, which points the way forward for the development of heterojunctions.

High‐Voltage Electrolyte Chemistry for Lithium Batteries

Abstract: Lithium batteries are currently the most popular and promising energy storage system, but the current lithium battery technology can no longer meet people's demand for high energy density devices. Increasing the charge cutoff voltage of a lithium battery can greatly increase its energy density. However, as the voltage increases, a series of unfavorable factors emerges in the system, causing the rapid failure of lithium batteries. To overcome these problems and extend the life of high‐voltage lithium batteries, electrolyte modification strategies have been widely adopted. Under this content, this review first introduces the degradation mechanism of lithium batteries under high cutoff voltage, and then presents an overview of the recent progress in the modification of high‐voltage lithium batteries using electrolyte modification strategies. Finally, the future direction of high‐voltage lithium battery electrolytes is also proposed.

Adina Rubella‐Like Microsized SiO@N‐Doped Carbon Grafted with N‐Doped Carbon Nanotubes as Anodes for High‐Performance Lithium Storage

Abstract: Microsized silicon oxide (SiO) has become a highly potential anode material for practical lithium‐ion batteries (LIBs) in virtue of its low cost and high capacity. However, its commercialization is still impeded by the low inherent conductivity and nonignorable volume expansion of SiO in the lithiation/delithiation processes. Herein, an in situ catalytic growth approach is developed for grafting N‐doped bamboo‐like carbon nanotubes (NCNTs) onto the polydopamine‐coated SiO microparticles, yielding a unique adina rubella‐like SiO@NC‐NCNT composite. The cross‐sectional scanning electron microscopy images reveal that the flexible middle‐carbon layer plays a crucial role in alleviating volume expansions and improving structural stability of SiO@NC‐NCNTs. Theoretical density functional theory simulation results further prove that the rational construction of ternary heterostructure can effectively balance lithium adsorption energies and greatly improve conductivity of SiO@NC‐NCNTs. As a result, the as‐fabricated SiO@NC‐NCNTs LIB anode shows a high reversible specific capacity of 1103.7 mA h g−1 at 0.2 A g−1 after 200 cycles with a high retention of 99.6% and an outstanding rate capability of 569 mA h g−1 at 5000 mA g−1. The strategy developed herein demonstrates a feasible avenue for developing high‐energy SiO‐based anodes for LIBs.

Synergizing Conformal Lithiophilic Granule and Dealloyed Porous Skeleton toward Pragmatic Li Metal Anodes

Abstract: Li metal is regarded as one of the most promising anodes for next‐generation rechargeable batteries. Nonetheless, infinite volume change and severe dendrite growth impede its practicability. To date, unremitting efforts have been devoted to stabilizing Li metal anode via the rational design of 3D current collectors. In this sense, optimizing Li nucleation behavior plays a pivotal role in alleviating the dendrite formation. Herein, a practically viable route is devised by in situ crafting lithiophilic CuSe granules on the dealloyed Cu skeleton (D‐Cu@CuSe). Persuasive electrochemical analysis and systematic theoretical calculation disclose the underlying Li nucleation mechanism on the CuSe overlayer. Impressively, the D‐Cu@CuSe‐Li symmetric cell can sustain a stable plating/stripping operation over 1000 h at a high depth of discharge at 62.5%. More crucially, when paired with high‐loading sulfur cathodes, D‐Cu@CuSe‐Li||S batteries harvest advanced areal capacity and stable cycling performance even under stringent working conditions of low negative‐to‐positive (N/P) (≈2) and electrolyte‐to‐sulfur (8 μL mgs−1) ratios. Overall, a fresh perspective into rationalizing current collector design is afforded, which extends Li utilization and cycling durability in the pursuit of pragmatic Li metal anodes.