In situ fabrication of a plasmonic Bi@Bi2O2CO3 core-shell heterostructure for photocatalytic CO2 reduction: structural insights into selectivity modulation.

The precise design of active sites and light absorbers is essential for developing highly efficient photocatalysts for CO2 reduction. Core-shell heterostructures constructed based on large-sized plasmonic Bi metals are ideal candidates because of the utilization of full-spectrum light and effective charge separation. However, the mechanism of selectivity modulation of large-sized Bi@semiconductor photocatalysts has yet to be explored in depth. Herein, a plasmonic Bi@Bi2O2CO3 core-shell heterostructure was successfully synthesized via a facile solvothermal treatment in deep eutectic solvents, demonstrating highly efficient photocatalytic CO2 reduction. This structure features a sizeable Bi sphere with a thin, epitaxially grown Bi2O2CO3 shell, which allows for the utilization of the entire light spectrum. Additionally, the oxygen vacancies in the Bi2O2CO3 shell can rapidly trap electrons transferred from the Bi core via Bi-O-Bi bonds, thereby forming abundant electron-rich interfaces that serve as the active sites for activating reactant molecules and facilitating the reaction.

Vision Improvement in Keratoconus Patients Trained with Perceptual Learning: A Randomized Controlled Trial.

BACKGROUND: Keratoconus (KC) is a corneal ectasia disease in which the vision of some patients cannot achieve satisfaction by spectacle corrections. However, not everyone can embrace contact lenses to achieve better vision. Perceptual learning (PL) is a potential treatment for vision improvement in such patients. PURPOSE: To investigate the effectiveness and maintenance of PL on vision improvement in KC patients corrected with spectacles. DESIGN: Randomized, double-blind clinical trial. PARTICIPANTS: Thirty-five non-progressive KC patients aged 9 years or older with unsatisfied spectacle-corrected vision were enrolled. METHODS: Non-progressive KC patients with best spectacle-corrected distance visual acuity (CDVA) of 0 to 1.0 logMAR (Snellen equivalent range 20/20 to 20/200) and contact lenses intolerant were enrolled. Eligible subjects were randomized into PL and control groups to receive PL and placebo training for 3 months, respectively. Spectacle-corrected visual acuity, contrast sensitivity function (CSF), stereoacuity, and visual functioning and quality of life questionnaires were measured at baseline, 3 months, and 6 months of follow-up. Statistics were analyzed following the intention-to-treat (ITT) principle. RESULTS: After 3 months of training, the CDVA of patients in the PL group improved as compared to the placebo group (0.17 ± 0.15 logMAR vs. 0.02 ± 0.06 logMAR; P = 0.0006). Eight out of seventeen (47.06 %) patients in the PL group reached CDVA improvement ≥ 2 lines (P=0.0010). This improvement persisted for at least 6 months (from baseline) as compared to the placebo group (0.17 ± 0.17 logMAR vs. 0.01 ± 0.07 logMAR; P = 0.0011). The increase of CSF in the PL group mainly was found for moderate spatial frequency (0.11 ± 0.17 log units at 3 cpd; 0.12 ± 0.19 log units at 6 cpd). Linear regression indicated that patients with worse initial CDVA achieved better gains in CDVA after PL (P = 0.009). No side effects were observed and no subjects quit because of training difficulties. CONCLUSION: Three-month perceptual learning improved vision in KC patients and the improvement maintained after 3 months of treatment cessation. The results indicate that perceptual learning may be a promising therapy for KC patients with unsatisfied spectacle-corrected visual acuity.

2D NiFe2O4/Ni(OH)2 Heterostructure-Based Self-Supporting Electrode With Synergistic Surface/Interfacial Engineering for Efficient Water Electrooxidation.

To meet the industrial demand for overall water splitting, oxygen evolution reaction (OER) electrocatalysts with low-cost, highly effective, and durable properties are urgently required. Herein, a facile confined strategy is utilized to construct 2D NiFe2O4/Ni(OH)2 heterostructures-based self-supporting electrode with surface-interfacial coengineering, in which abundant and ultrastable interfaces are developed. Under the high molar ratio of Ni/Fe, both spinel oxide and hydroxides phases are formed simultaneously to obtain 2D NiFe2O4/Ni(OH)2 heterostructure. The in-depth analysis indicates that the NiFe2O4/Ni(OH)2 interface displays strong electronic interactions and triggers the formation of crystalline-amorphous coexisting catalytic active NiOOH. Meanwhile, the stable catalyst-collector interface favors the electron transfer and oxygen molecules transport. The resultant 2D NiFe2O4/Ni(OH)2@CP electrode exhibits superior OER performance, including a low overpotential of 389 mV and a long operating time of 12 h at 1 A cm-2. This work paves a novel method for fabricating efficient and low-cost electrocatalysts for electrochemical conversation devices.

CO2 coordination-driven top-down synthesis of a 2D non-layered metal-organic framework.

Combining the physical advantages of two-dimensional (2D) inorganic nanosheets and the modular design and programmed structure of metal-organic frameworks (MOFs), 2D MOFs remain at the forefront of functional material research. Despite tremendous efforts, precise control in the synthesis of 2D nonlayered MOFs with predesigned topology for desired applications remains challenging. Success in the bottom-up synthesis of 2D nonlayered MOFs via ligand exchange motivated us to incorporate partial BTC (BTC = 1,3,5-benzenetricarboxylate) ligand dissociation and CO2 capped coordination into the top-down treatment of bulk Cu-BTC MOF, leading to successful conversion of a 3D nonlayered network to a 2D Cu-based topological structure. Notably, a supercritical CO2-containing solvent mixture is employed to provide the desired defect and coordination engineering. Thus, our work introduces a new top-down concept based on modulated synthesis to fabricate high-quality 2D nonlayered MOFs for the first time.

2D amorphous bi-metallic NiFe nitrides for a high-efficiency oxygen evolution reaction.

Two-dimensional bi-metallic NiFe nitrides (2D NiFe-N) are successfully synthesized in the designed ternary deep eutectic solvents under the guidance of DFT calculations. Taking advantage of the unique properties of large-size, ultrathin amorphous 2D structure and modulable electronic structure, the NiFe0.05-N exhibits extraordinary OER performance with relatively low overpotential of 238 mV at 10 mA cm-2 and durable stability.

Generation of 2D nonlayered ferromagnetic VO2(M) nanosheets induced by strain engineering of CO2.

Two-dimensional (2D) nonlayered ferromagnets displaying high Curie temperatures, sizable magnetic anisotropy levels, and large spin polarizations are emerging as promising 2D ferromagnetics. However, the difficulties in synthesizing 2D nonlayered intrinsic ferromagnets have largely limited their development. Herein, defect-rich 2D nonlayered VO2(M) nanosheets have been fabricated by deploying straining engineering of CO2 on the metal-insulator transition (MIT) of VO2. Above TMIT, the strong strain engineering of CO2 in the R phase of VO2 generated a very large number of atomic defects in its 3D crystal structure, and as a result facilitated conversion of the defective 3D network to 2D nanosheets along the c-axis. The as-prepared 2D defective VO2(M) nanosheets displayed unique room-temperature ferromagnetism, attributed to the symmetry breaking triggered by the disordered atomic structure combined with the 3D-to-2D transformation.

An advanced FeCoNi nitro-sulfide hierarchical structure from deep eutectic solvents for enhanced oxygen evolution reaction.

A tri-metal material system of FeCoNi-based nitro-sulfide (FeCoNi-NS) hierarchical structure has been successfully synthesized via a deep eutectic solvent annealing process. The as-prepared FeCoNi-NS possesses interesting N,S-binary heteroatoms evenly doped with Fe, Co, and Ni. By taking advantage of the unique structure including multi-metal sites, high BET area and porous structures, the as-prepared FeCoNi-NS exhibited excellent oxygen evolution reaction (OER) performance, achieving a current density of 10 mA cm-2 at an overpotential of 251 mV and a low Tafel slope of 58 mV dec-1 in 1 M KOH. Furthermore, FeCoNi-NS also demonstrated highly efficient mass/charge transportation, long-term stability with 2% deactivation after ten hours continuous operation and high faradaic efficiency of 98%. Such a facile synthetic strategy is applicable to the fabrication of more mutil-metal hierarchical structures for energy conversion and storage.

Thermal, electrochemical and radiolytic stabilities of ionic liquids.

Research on ionic liquids has achieved rapid progress in the last several decades. Stability is a prerequisite for the application of ionic liquids. Ionic liquids may be used at elevated temperature, as electrolytes, or under irradiation. Therefore, the thermal, electrochemical, and radiolytic stabilities of ionic liquids are important and need to be known before their usage. Many research papers and some reviews on the stabilities of ionic liquids have been published. However, new results are continuously being published and a comprehensive review and perspective on this topic are still urgently needed. In this perspective, we intend to provide a comprehensive review including characterization methods, the effects of chemical composition of the ionic liquids on the thermal, electrochemical, and radiolytic stabilities of ionic liquids, respectively. Moreover, the thermal stability of some special types of ionic liquids such as poly(ionic liquids) and mixed ionic liquids, and the thermal and electrochemical stabilities of protic ionic liquids are discussed too. For thermal stability, the interactions between ions are less important than the individual anions and cations. The decomposition temperature is mainly determined by the less-stable ion, usually the anion. For electrochemical stability, the electrochemical window is determined by both the cation and anion. The less stable ion could influence the stability by interaction between the generated species from the decomposition with the more stable ion (opposite ion). This perspective is helpful for people to avoid using unstable ionic liquids and choose suitable ionic liquids.

An ambient temperature, CO2-assisted solution processing of amorphous cobalt sulfide in a thiol/amine based quasi-ionic liquid for oxygen evolution catalysis.

We report the synthesis of CoSx nanosheets from a 1,2-ethanedithiol/n-butylamine quasi-ionic liquid with the assistance of compressed CO2 at ambient temperature. The CoSx achieves a current density of 10 mA cm-2 at an overpotential of 271 mV for the oxygen evolution reaction. Furthermore, our method is applicable to the fabrication of other transition metal chalcogenides.

Highly Efficient, Green, and Scalable ß-Cyclodextrin-Assisted Aqueous Exfoliation of Transition-Metal Dichalcogenides: MoS2 and ReS2 Nanoflakes.

The ß-cyclodextrin-assisted aqueous-exfoliation method was used to prepare transition-metal dichalcogenide (TMD) nanosheets, in a cheap, highly efficient, scalable and environmentally friendly manner. As study cases, MoS2 and ReS2 nanoflakes were prepared according to this method. Particularly, the effective exfoliation of ReS2 crystals in an aqueous environment was observed for the first time. Moreover, exfoliated nanomaterials can be readily utilized in hydrogen evolution reactions (HERs) as noble-metal-free catalysts. This work provides new opportunities for highly efficient exfoliation of TMDs and other 2D nanomaterials into few-layer nanosheets in aqueous media. Their production process showed high biocompatibility, broad applicability and excellent sustainability.

Large-Scale, Highly Efficient, and Green Liquid-Exfoliation of Black Phosphorus in Ionic Liquids.

We developed a facile, large-scale, and environmentally friendly liquid-exfoliation method to produce stable and high-concentration dispersions of mono- to few-layer black phosphorus (BP) nanosheets from bulk BP using nine ionic liquids. The prepared suspensions can stabilize without any obvious sedimentation and aggregation in ambient air for one month. In particular, the concentration (up to 0.95 mg mL(-1)) of BP nanoflakes obtained in 1-hydroxyethyl-3-methylimidazolium trifluoromethansulfonate ([HOEMIM][TfO]) is the highest reported for BP nanosheets dispersions. This work provides new opportunities for preparing atomically thin BP nanosheets in green, large-scale, and highly concentrated processes and achieving its in situ application.

A linear graphene edge nanoelectrode.

A nanometer-thick linear graphene edge nanoelectrode was constructed based on the edge plane of chemical vapor deposition (CVD) grown few-layer graphene, which showed much better electrochemical performance compared with traditional carbon fibre microelectrodes.

A microfluidic linear node array for the study of protein-ligand interactions.

We have developed a microfluidic device for the continuous separation of small molecules from a protein mixture and demonstrated its practical use in the study of protein-ligand binding, a crucial aspect in drug discovery. Our results demonstrated dose-dependent binding between bovine serum albumin (BSA) and its small-molecule site marker, Eosin Y (EY), and found that the binding reached a plateau when the BSA : EY ratio was above 1, which agreed with the eosin binding capacity of BSA reported in literature. By streamline control using a combination of two fundamental building blocks (R and L nodes) with a microdevice operated at a high flow rate (up to 1300 µL h(-1)), a solution barrier was created to "filter" off protein/protein-ligand complexes such that the small unbound molecules were isolated and quantified easily. The percentage decrease of small molecules with increasing protein concentration indicated the presence of binding events. Several fluorophores with different molecular weights were used to test the performance of the microfluidic "filter", which was tunable by 1) the total flow rate, and/or 2) the flow distribution ratio between the two device inlets; both were easily controllable by changing the syringe pump settings. Since the microdevice was operated at a relatively high flow rate, aliquots were easily recovered from the device outlets to facilitate off-chip detection. This microfluidic design is a novel and promising tool for preliminary drug screening.