Search

Promoting electron-hole separation and migration and lowering the overpotential of hydrogen evolution reactions are two effective solutions for improving photocatalytic hydrogen performance. Suitable co-catalyst and appropriate interfacial contacts can effectively lower overpotential and can also construct an electric field at the interface to increase the separation efficiency of the carriers. In this work, we design and fabricate a 2D-2D type of Ni2P co-catalyst modified with ZnIn2S4 for boosting the performance of photocatalytic hydrogen evolution. As a co-catalyst, the 2D Ni2P nanosheets exhibit a lower overpotential and smaller charge transfer resistance in hydrogen evolution reactions, and is much improved in both respects compared to Ni2P nanoparticles. Based on this, 2D/2D Ni2P/ZnIn2S4 nanohybrids with large contact regions and shorter transmission distances of the charges were fabricated, which effectively improve the separation of photo induced carriers and the interfacial charge transfer. By taking advantage of the above features, the fabricated 2D-2D Ni2P/ZnIn2S4hybrid exhibits a superior hydrogen evolution rate of 2066 μmol·h−1·g−1 under visible light irradiation, and the apparent quantum yield was 7.7% at 420 ± 20 nm. This activity far exceeds performance of the 0D/2D Ni2P/ZnIn2S4 hybrid, and is ascribed to better charge separation and accelerated surface reactions of the Ni2P nanosheets.

Metal-organic frameworks (MOFs) intended for C2H2/CO2 separation should possess high C2H2/CO2 adsorption selectivity and large C2H2 adsorption capacity. Here we report the scalable synthesis of a cage-interconnected microporous MOF (JNU-2). Dynamic column breakthrough experiments on JNU-2 manifest a C2H2-capture capacity of 3.08 mmol g−1 for an equimolar C2H2/CO2 mixture at 298 K and 1 bar, exceeding the benchmark materials such as UTSA-74a and FeNi-M’MOF. Meanwhile, the selectivity factor was estimated to be ca. 1.5 for JNU-2 and consistent with the increasing flow rate. Theoretical calculations confirm that the surface of the JNU-2 framework enables preferential binding of C2H2 over CO2 via multiple C–H···O, C–H···N, and π-complexation interactions. More importantly, JNU-2 retains its C2H2/CO2 separation capacity under highly humid conditions. Although the equilibrium adsorption of H2O is much higher than those of C2H2 and CO2, kinetic studies reveal that the diffusion of C2H2 and CO2 in JNU-2 is more than two orders of magnitude faster than that of H2O. A balanced hydrophobicity/hydrophilicity of the MOF framework surface might be the key to achieving large adsorption capacity for nonpolar gas molecule while minimizing the competition of water vapor adsorption.

Deep-red and near-infrared organic light-emitting diodes (DR/NIR-OLEDs) showed a wide range of applications such as healthcare and night-vision. However, red emitters generally demonstrated severe non-radiative emission due to energy gap law, and the development of efficient deep-red and near-infrared thermally activated delayed fluorescence (DR/NIR-TADF) materials was still under-researched by now. Herein, we designed and synthesized a series of efficient red/DR TADF emitters. Their emission wavelengths were rationally regulated into DR region via introducing strong electron-withdrawing groups from pyridinyl (PY) to trifluoromethyl (CF3) and to cyano (CN). The internal conversion (IC) process of these emitters was suppressed greatly via the incorporation of fused polycyclic aromatics (dibenzo[a,c]phenazine). Furthermore, the structural relaxation of their excited states was also reduced due to the restricted σ bond rotation between donor (D) and acceptor (A) units. As a result, these red/DR emitters showed high photoluminescence quantum yields (PLQYs) and excellent electrofluorescence performance. Particularly, OLEDs based on CN-TPA showed remarkably high maximum external quantum efficiencies (EQEs) of 22.80% at 668 nm, 18.41% at 688 nm and 15.05% at 698 nm, which were among the best values for reported TADF emitters. This result may provide a straightforward design strategy for efficient DR/NIR TADFs through optimizing the acceptor strength of rigidified polyaromatic frameworks.

This study was aimed to investigate the influence of low-frequency alternative pulse current (APC) with square wave on the disinfection performance of carbon fiber-based flow-through electrode system (FES) towards a model bacterium (Escherichia coli). The FES disinfection under direct current (DC) supply was limited by the weak disinfection efficiency of cathode. Compared with DC supply (less than 1 log removal), FES under APC supply achieved superior disinfection performance (over 6 log removal) at the voltage of 3 V and flow rate of 125 mL/min. The optimum condition was acquired when pulse cycle time (T) equaled to hydraulic retention time (HRT), i.e. HRT/T = 1, corresponding to the low frequency (less than 1 Hz), under which the disinfection performance was improved by alternating of anode and cathode. In-situ sampling experiments revealed that redox reactions were carried out alternatively in each electrode, and both electrodes made great contributions to disinfection under APC supply, which was significantly different from DC supply. In addition, FES disinfection under APC supply also caused irreversible damage to bacterial cells, resulting in no bacterial regrowth/reactivation during storage, and guaranteed low energy consumption (11.4 ~ 12.1 Wh/m3) with high flow rate (100 ~ 125 mL/min). Therefore, the development of a novel FES under APC supply provided exciting possibilities for future application of electrochemical disinfection to achieve superior disinfection performance with no bacterial regrowth and low energy consumption.

Flexible sensing materials have become scientific hotspot in smart sensors. For outdoor uses, wearable electronic sensors must meet the challenges from water, sweat, or other liquids. Herein, a simple strategy was described to fabricate nanocomposite film of thermoplastic elastomer and carbon nanotubes (TPE/CNTs) at air/water interface for wearable electronics with liquid repelling property. Firstly, mixture suspension of TPE and CNTs was pumped into water and kept still to form a TPE/CNTs sheet at the water surface. Then the sheet was stabilized by spraying with N-hexane and transferred out of the air/water interface to obtain a free-standing TPE/CNTs film. The resultant film is conductive with a resistance of 15KΩ and superhydrophobic with a CA of 160°. When applied as a sensor, it shows excellent performance with superior sensitivity (The gauge factor is about 1), fast response time (100–150 ms), stable response over 1000 stretching-relaxing cycles, and wide sensing ranges (stretching: over 76%). Importantly, it can be used in wet conditions, making it capable to be wearable electronic devices for fast response, long-term and reliable human behavior monitoring.

Superhydrophobic poly(ethylene terephthalate) (PET) fabrics were firstly fabricated by one-pot in situ Stober reaction of tetraethylorthosilicate (TEOS) and dodecyltrimethoxysilane (DTMS), in which the as-formed silica particles roughened the fiber surfaces and the hydrolyzed dodecyltrimethoxysilane hydrophobized the fabrics. Then the superhydrophobic fabrics were turned superamphiphobic after modification with perfluorodecyltrichlorosilane (PFDTS), with water and oil contact angles higher than 150°. The synergistic hydrophobization of DTMS, PFDTS and PDMS made the roughened fabrics easy to be superamphiphobic using very low concentration of PFDTS. Meanwhile, the as-obtained superamphiphobic fabric showed excellent chemical robustness even after exposure to different chemicals, such as acid, base, and salt. Importantly, the fabrics were durable to 100 cycles of laundries, 1000 cycles of mechanical abrasion as well as long time exposure to UV irradiation without apparently changing the amphiphobicity. Also, the surface of the superamphiphobic fabrics showed excellent blood stain resistance properties.

Herein, a convenient and environment-friendly grafting and reduction strategy was used to anchor bimetallic Ag-Cu nanoparticles on polypropylene (PP) fabrics. The as-prepared samples were characterized by various techniques including FE-SEM, XRD, EDX, XPS and FT-IR. The as-prepared sample exhibits excellent activity on the catalytic reduction of highly concentrated 4-NP, and the synergistic effect between Ag and Cu nanoparticles was proved. The entire catalytic reduction was generally considered to obey pseudo-order kinetics, affording high conversion even after 15 successive recycles. These results showed that the PP based composite with Ag-Cu nanoparticles effectively provided superb catalytic efficiency and stability in 4-nitrophenol reduction, and the PP based composites were suitable in practical applications for the treatment of diverse waste water.

Flexible and wearable sensors are of extreme importance for various practical applications in complex environments, such as electronic skin, body motion detection, etc. However, preparation of cost-effective and superhydrophobic wearable sensors with excellent flexibility, anti-corrosion, outstanding sensitivity and environmental adaptability remains challenging. Herein, a superhydrophobic flexible film is fabricated by spray-coating thermoplastic elastomer (TPE) solution on the upside of a multi-walled carbon nanotube (MWCNTs) sheet formed at the air/water interface, followed by treating the downside of MWCNTs sheet with polydimethylsiloxane (PDMS) pumped into the water. In the process, the covering of TPE on the MWCNTs made the sheet shrunk and increased the density of the conductive network. PDMS coating enhanced superhydrophobicity of the film, and binding fastness of the MWCNTs. The obtained sandwich-like TPE/MWCNTs/PDMS film had superior conductive sensitivity, large strain range (80%), fast and stable response time (60–80 ms) with great stability over 1000 stretching-relaxing cycles. Benefiting from the favorable superhydrophobic property, the fabricated film was capable of being put into liquid environment for quantifying the resistance under humid environments including moisture, acid, basic and salt conditions. It can be effectively used to measure wrist pulse and monitor various movements associated with different human body joints, such as finger, wrist, elbow. Moreover, the sensing film was able to capture the continuous signals in diverse atmosphere such as the area change of film, and the real-time stress response of drop impact. This study affords an innovative and promising track for multifunctional wearable sensors with wide applications in a harsh environment.

Mechanically durable superhydrophobic surfaces on cotton fabrics were fabricated by binding polystyrene nanoparticles onto fibers with aluminum phosphate (AP) followed by coating with polydimethylsiloxane (PDMS) as low surface energy substance. Decoration of nanoparticles roughened the fabric surface and coating with AP made stable the roughening structures. The as-prepared fabric surfaces not only showed excellent stability to acid, alkali, salt, organic solvent and UV irradiation, but also could maintain their superhydrophobicity after abrasion of 2000 or laundering of 35 cycles. The combination of inorganic adhesives AP and organic PDMS greatly enhanced the mechanical stability of the superhydrophobicty of the cotton substrate. Meanwhile, the obtained superhydrophobic fabrics showed excellent self-cleaning property.