Lanthanide‐Coordinated Black Phosphorus Wu, Lie; Wang, Jiahong; Lu, Jiang ...
Small (Weinheim an der Bergstrasse, Germany),
July 19, 2018, Letnik:
14, Številka:
29
Journal Article
Recenzirano
Black phosphorus (BP) possesses unique physical properties and, owing to its intrinsic instability, the proper surface and chemical coordination is the key point in many applications. Herein, a ...facile and efficient surface lanthanide‐coordination strategy based on lanthanide (Ln) sulfonate complexes is designed to passivate and functionalize different BP‐based nanostructures including quantum dots, nanosheets, and microflakes. By means of Ln–P coordination, the lone‐pair electrons of phosphorus are occupied, thus preventing oxidation of BP, and the LnL3@BP exhibits excellent stability in both air and water. Furthermore, accompanied by the original photothermal performance of BP nanostructures, the Gd‐coordinated BP has high R1 relativities in magnetic resonance (MR) imaging, and other Ln (Tb, Eu, and Nd) coordinated BP structures exhibit fluorescence spanning the visible to near‐infrared regions. Not only is LnL3 surface passivation an efficient method to enhance the stability of BP, but also the MR or fluorescence derived from lanthanide ions extends the application of BP to optoelectronics and biomedical engineering.
A facile lanthanide‐coordination strategy based on lanthanide sulfonate complexes is established for surface modification of black phosphorus (BP)‐based nanostructures, including quantum dots, nanosheets, and microflakes. It presents an efficient method to protect BP, and the magnetic resonance or fluorescence derived from the lanthanide enables the functionalization of BP for extending its application range.
Delicate modulations of CO2 activation and charge carrier separation/migration are challenging, yet imperative to augment CO2 photoreduction efficiency. Herein, by supporting diethylenetriamine ...(DETA)‐functionalized Cd0.8Zn0.2S nanowires on the exterior surface of hollow Co9S8 polyhedrons, hierarchical Co9S8@Cd0.8Zn0.2S‐DETA nanocages are fabricated as an S‐scheme photocatalyst for reducing CO2 and protons to produce syngas (CO and H2). The amine groups strengthen adsorption and activation of CO2, while the “nanowire‐on‐nanocage” hierarchical hollow heterostructure with an S‐scheme interface boosts separation and transfer of photoinduced charges. Employing Co(bpy)32+ as a cocatalyst, the optimal photocatalyst effectively produces CO and H2 in rates of 70.6 and 18.6 µmol h−1 (i.e., 4673 and 1240 µmol g−1 h−1), respectively, affording an apparent quantum efficiency of 9.45% at 420 nm, which is the highest value under comparable conditions. Ultraviolet photoelectron spectroscopy, Kelvin probe, and electron spin resonance confirm the S‐schematic charge‐transfer process in the photocatalyst. The key COOH* species responsible for CO2‐to‐CO reduction is detected by in‐situ diffuse reflectance infrared Fourier transform spectroscopy and endorsed by density functional theory calculations, and thus a possible CO2 reduction mechanism is proposed.
Hierarchical Co9S8@Cd0.8Zn0.2S‐diethylenetriamine (DETA) hybrid nanocages are created by supporting DETA‐functionalized Cd0.8Zn0.2S nanowires on the exterior surface of hollow Co9S8 polyhedrons and they are applied as an S‐scheme photocatalyst for efficient syngas production from CO2 and protons, yielding a superior apparent quantum efficiency of 9.45% at 420 nm.
Flexible electronics attached to skin for healthcare, such as epidermal electronics, has to struggle with biocompatibility and adapt to specified environment of skin with respect to breath and ...perspiration. Here, we report a strategy for biocompatible flexible temperature sensors, inspired by skin, possessing the excellent permeability of air and high quality of water-proof by using semipermeable film with porous structures as substrate. We attach such temperature sensors to underarm and forearm to measure the axillary temperature and body surface temperature respectively. The volunteer wears such sensors for 24 hours with two times of shower and the in vitro test shows no sign of maceration or stimulation to the skin. Especially, precise temperature changes on skin surface caused by flowing air and water dropping are also measured to validate the accuracy and dynamical response. The results show that the biocompatible temperature sensor is soft and breathable on the human skin and has the excellent accuracy compared to mercury thermometer. This demonstrates the possibility and feasibility of fully using the sensors in long term body temperature sensing for medical use as well as sensing function of artificial skin for robots or prosthesis.
Prussian blue analogs (PBAs) are considered as reliable and promising cathode materials for aqueous Zn‐ion batteries (AZIBs), but they suffer from low capacity and poor cycling stability due to ...insufficient active sites and structural damage caused by the ion insertion/extraction processes. Herein, a template‐engaged ion exchange approach has been developed for the synthesis of Co‐substituted Mn‐rich PBA hollow spheres (CoMn‐PBA HSs) as cathode materials for AZIBs. Benefiting from the multiple advantageous features including hollow structure, abundant active sites, fast Zn2+ ion diffusion, and partial Co substitution, the CoMn‐PBA HSs electrode shows efficient zinc ion storage properties in terms of high capacity, decent rate capability and prolonged cycle life.
Co‐substituted Mn‐rich Prussian Blue Analog (PBA) hollow spheres (CoMn‐PBA HSs) are rationally designed and synthesized through an efficient self‐templating approach. Benefiting from the hollow structure and partial Co substitution, the CoMn‐PBA HSs electrode exhibits enhanced zinc ion storage performance with high capacity, favorable rate capability, and impressive cycling stability.
Here we synthesize novel asymmetric all-solid-state paper supercapacitors (APSCs) based on amorphous porous Mn3O4 grown on conducting paper (NGP) (Mn3O4/NGP) negative electrode and Ni(OH)2 grown on ...NGP (Ni(OH)2/NGP) as positive electrode, and they have attracted intensive research interest owing to their outstanding properties such as being flexible, ultrathin, and lightweight. The fabricated APSCs exhibit a high areal C sp of 3.05 F/cm3 and superior cycling stability. The novel asymmetric APSCs also exhibit high energy density of 0.35 mW h/cm3, high power density of 32.5 mW/cm3, and superior cycling performance (<17% capacitance loss after 12 000 cycles at a high scan rate of 100 mV/s). This work shows the first example of amorphous porous metal oxide/NGP electrodes for the asymmetric APSCs, and these systems hold great potential for future flexible electronic devices.
The radiation of electromagnetic and mechanical waves depends not only on the intrinsic properties of the emitter but also on the surrounding environment. This principle has laid the foundation for ...the development of lasers, quantum optics, sonar, musical instruments and other fields related to wave–matter interaction. In the conventional wisdom, the environment is defined exclusively by its eigenstates, and an emitter radiates into and interacts with these eigenstates. Here we show experimentally that this scenario breaks down at a non-Hermitian degeneracy known as an exceptional point. We find a chirality-reversal phenomenon in a ring cavity where the radiation field reveals the missing dimension of the Hilbert space, known as the Jordan vector. This phenomenon demonstrates that the radiation field of an emitter can become fully decoupled from the eigenstates of its environment. The generality of this striking phenomenon in wave–matter interaction is experimentally confirmed in both electromagnetic and acoustic systems. Our finding transforms the fundamental understanding of light–matter interaction and wave–matter interaction in general, and enriches the intriguing physics of exceptional points.The modes of the radiation field generated from an emitter are usually determined by the eigenstates of the surrounding environment. However, this scenario breaks down in a non-Hermitian system, at the spectral degeneracy known as an exceptional point.
Wearable touch panels, a typical flexible electronic device, can recognize and feed back the information of finger touch and movement. Excellent wearable touch panels are required to accurately and ...quickly monitor the signals of finger movement as well as the capacity of bearing various types of deformation. High‐performance thermistor materials are one of the key functional components, but to date, a long‐standing bottleneck is that inorganic semiconductors are typically brittle while the electrical properties of organic semiconductors are quite low. Herein, a high‐performance flexible temperature sensor is reported by using plastic Ag2S with ultrahigh temperature coefficient of resistance of −4.7% K−1 and resolution of 0.05 K, and rapid response/recovery time of 0.11/0.11 s. Moreover, the temperature sensor shows excellent durability without performance damage or loss during force stimuli tests. In addition, a fully flexible intelligent touch panel composed of a 16 × 10 Ag2S‐film‐based temperature sensor array, as well as a flexible printed circuit board and a deep‐learning algorithm is designed for perceiving finger touch signals in real‐time, and intelligent feedback of Chinese characters and letters on an app. These results strongly show that high‐performance flexible inorganic semiconductors can be widely used in flexible electronics.
A fully flexible intelligent thermal touch panel based on the intrinsically plastic Ag2S semiconductor can well perceive finger touch signals in real‐time and displays intelligent feed back of Chinese characters and letters on an app.
The counterions of polydiallyldimethylammonium (PDADMA) coatings were altered by incubation in aqueous solutions of different electrolytes. Oil de‐wetting on the resulting polycationic surfaces upon ...water action exhibited a straightforward connection with the Jones–Dole viscosity B‐coefficient (Bη) sign of surface counteranions. Upon water action, surface counteranions with negative Bη render PDADMA coatings oil‐adhering, but those with positive Bη furnish PDADMA coatings with excellent self‐cleaning. The oil‐adhering PDADMA surfaces can become self‐cleaning upon water action in response to the Bη of surface counteranions sign‐switching with increasing water temperature. Courtesy of surface counter‐anions with Bη>0, self‐cleaning PDADMA coatings enable not only conversion of conventional meshes into self‐cleaning membranes for oil/water separation, but also regioselective maneuver of oil flow on polycationic surfaces according to the Bη sign of surface counteranions patterned atop.
Polydiallyldimethylammonium surfaces with surface counterions with a positive Jones–Dole viscosity coefficient (Bη) exhibit excellent self‐cleaning function upon water action. Those with surface counterions with negative Bη reasonably adhere to oil under water. This ion‐specific effect enables the guidance of the oil flow on ionic surfaces upon water action according to the nature of surface (counter)ions.
The exploration of highly active, durable, and cost-effective electrocatalysts for the oxygen reduction reaction (ORR) is indispensable for several important energy conversion technologies. ...Significant achievements have been made with numerous efforts devoted by the academic and industrial researchers. In this review, from a more practical point of view, the tests and experiments at the membrane electrode assembly (MEA) level are accentuated due to the fact that the rotating disk electrode (RDE) level performance cannot be transformed directly into the MEA level. Four major categories of the current ORR electrocatalysts are discussed, namely, platinum group metal (PGM or noble) catalysts, non-PGM catalysts, carbon-based catalysts, and single-atom-based catalysts. The advantages and shortcomings, along with the performance achieved by the catalysts, are briefly reviewed, and the improvement in the rational design approaches is emphasized at the full-cell level. Finally, the present challenges and prospects are discussed for developing advanced ORR electrocatalysts.
Proton exchange membrane fuel cells (PEMFCs) and metal-air batteries have attracted considerable attention as the promising supply of clean energy for residential applications, vehicles, and stationary power systems owing to their high energy conversion efficiency, high energy density, low emissions, and high consistency. Nevertheless, the widespread applications of PEMFCs or metal-air batteries are still severely hampered by the sluggish oxygen reduction reaction (ORR) at the cathodic side, which needs considerable amounts of Pt to compensate for this issue. Herein, the research progress on the ORR electrocatalysts, mainly including platinum group metal (PGM or noble) catalysts, non-PGM catalysts, carbon-based catalysts, and single-atom-based catalysts, is critically reviewed. From the perspective of practical applications, one great concern is whether an effective ORR catalyst at the rotating disk electrode (RDE) level could be competent at the membrane electrode assembly (MEA) level. We put emphasis on why and how to bring about the rational design of the electrocatalysts to overcome the sluggish ORR kinetics, particularly underlining the applicable approaches by which the RDE level performance could be translated into the MEA level. With considerable efforts and attentions given on the systematic progress of ORR electrocatalysts, it is expected that the clean and sustainable energy can be foreseeable in the near future.
Exploring highly active and durable electrocatalysts for oxygen reduction reaction (ORR) is indispensable for several important energy conversion technologies. In this review, we provide some discussion about the current ORR electrocatalysts from the perspective of practical applications. The advantages and shortcomings, along with the performance achieved by the catalysts are briefly reviewed, and the improvement in the rational design approaches are emphasized at the full-cell level. Finally, the present challenges and prospects are discussed for developing advanced ORR electrocatalysts.
Memcapacitors are emerging as an attractive candidate for high‐density information storage due to their multilevel and adjustable capacitances and long‐term retention without a power supply. However, ...knowledge of their memcapacitive mechanism remains unclear and accounts for the limited implementation of memcapacitors for multilevel memory technologies. Here, repeatable and reproducible quaternary memories fabricated from hybrid perovskite (CH3NH3SnBr3) memcapacitors are reported. The device can be modulated to at least four capacitive states ranging from 0 to 169 pF with retention for 104 s. Impressively, an effective device yield approaching 100% for quaternary memory switching is achieved by a batch of devices; each state has a sufficiently narrow distribution that can be distinguished from the others and is superior to most multilevel memories that have a low device yield as well as an overlapping distribution of states. The memcapacitive switching stems from the modulated p–i–n junction capacitance triggered by Br− migration, as demonstrated by in situ element mapping, X‐ray photoelectron spectra, and frequency‐dependent capacitance measurements; this mechanism is different from the widely reported memristive switching involving filamentary conduction. The results provide a new way to produce high‐density information storage through memcapacitors.
An independent memcapacitor for quaternary memory is achieved. Four capacitive states, “OFF”, “ON1”, “ON2”, and “ON3”, are able to be repeatedly and reproducibly written/read/erased in an ITO/CH3NH3SnBr3/Au sandwich‐like device. The memcapacitive switching stems from Br– migration to modulate the p–i–n junction capacitance, which is different and independent from resistance switching in memristors.
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