Multistep Surface Trap State Finishing Based on in Situ One-Step MOF Modification over Hematite for Dramatically Enhanced Solar Water Oxidation

Lotus leaf-inspired poly(lactic acid) nanofibrous membranes with enhanced humidity resistance for superefficient PM filtration and high-sensitivity passive monitoring

The biomimetic design principles offer promising solutions to fabrication of multifunctional nanofibrous membranes (NFMs) with on-demand hierarchies and properties. Herein, a combined electrospinningelectrospray approach was employed to firmly anchor MOF nanocrystals onto poly(lactic acid) (PLA) nanofibers, resembling the naturally occurring dense protrusions at the lotus leaf. The formation of unique MOF-protruding superstructures gave rise to an exceptional combination of increased electroactivity, in-situ electret properties and charge regeneration mechanisms, as well as remarkable humidity resistance. With 8 wt% bioinspired MOF-protrusions for the electrospunelectrosprayed PLA NFMs (BM-PLA8), the initial surface potential was elevated to 3.0 kV and slightly decreased to 2.6 kV after 7-day ageing, in clear contrast to only 1.1 and 0.6 kV for the normal PLA, respectively. Moreover, the tribo-output voltage and current were significantly promoted for BM-PLA8 (64.5 V and 151.6 nA), demonstrating high humidity resistance and long-term robustness even at 90 % RH. It conferred distinct improvements in air filtration performance for BM-PLA8 even at the highest airflow velocity of 85 L/min (below 250 Pa, 99.9 % and 95.0 % removal of PM2.5 and PM0.3, respectively), far surpassing the normal PLA counterpart (nearly 350 Pa, 89.5 % and 75.8 %). Arising from the respiration-driven charge regeneration mechanisms, passive respiratory monitoring of high sensitivity was demonstrated for BM-PLA8, showing great promise for efficient healthcare under the challenging circumstances.

High-performance bismuth vanadate photoanodes cocatalyzed with nitrogen, sulphur co-doped ferrocobalt-metal organic frameworks thin layer for photoelectrochemical water splitting

In this study, we prepare a highly efficient BiVO4 photoanode co-catalyzed with an ultrathin layer of N, S co-doped FeCo-Metal Organic Frameworks (MOFs) for photoelectrochemical water splitting. The introduction of N and S into FeCo-MOFs enhances electron and mass transfer, exposing more catalytic active sites and significantly improving the catalytic performance of N, S co-doped FeCo-based MOFs in water oxidation. The optimized BiVO4/NS-FeCo-MOFs photoanode exhibits impressive results, with a photocurrent density of 5.23 mA cm-2 at 1.23 V vs. Reversible Hydrogen Electrode (RHE) and an incident photon-to-charge conversion efficiency (IPCE) of 74.4 % at 450 nm in a 0.1 M phosphate buffered solution (pH = 7). These values are 4.84 times and 6.2 times higher than those of the original BiVO4 photoanode, respectively. Furthermore, the optimized BiVO4/NS-FeCo-MOFs photoanode demonstrates exceptional long-term stability, maintaining 96 % of the initial current after five hours.

Revealing the Essential Role of Iron Phosphide and its Surface-Evolved Species in the Photoelectrochemical Water Oxidation by Gd-Doped Hematite Photoanode

Phosphates are easily derived from transition metal phosphides under natural conditions, and the real roles of these two in catalytic reactions are not yet clear. Here, a multiphase FeP/Gd-Fe₂ O₃ shell-core structure photoanode was constructed and explored regarding the real role of FeP and its surface-reconstructed iron phosphate (Fe-Pi) in photoelectrochemical water oxidation. The FeP/Gd-Fe₂ O₃ photoanode exhibited an excellent photocurrent density of 2.56 mA cm^-2 at 1.23 V versus the reversible hydrogen electrode, up to 4 times greater than those of the pristine α-Fe₂ O₃ (0.64 mA cm^-2 ). Detailed studies showed that FeP could act as a photosensitizer to enhance light absorption and as a conductive layer to accelerate charge transfer. The FeP significantly enhanced the incident photon-to-current conversion efficiency of the photoanode and improved the electron transition within the photoanode. Naturally evolved Fe-Pi on the surface provided more active sites for water oxidation. They effectively passivated the surface capture state and synergistically inhibited the electron-hole recombination. Moreover, the in-situ constructed multiphase catalyst had a smaller interfacial contact resistance than the intentionally decorative cocatalyst. This work provides new insight into the understanding of the essential role of transition metal phosphides and their surface-reconstructed species in catalytic reactions.

An efficient strategy to boost the directed migration of photogenerated holes by introducing phthalocyanine as a hole extraction layer

Phthalocyanine with adjustable band energy and a binding group acts as a hole extraction layer to accelerate hole transfer from Ti-Fe2O3 to CoPi, and thus improves the PEC water oxidation performance of Ti-Fe2O3.

The electrochemiluminescence coreactant accelerator of metal-organic frameworks grafted with N-(aminobutyl)-N-(ethylisoluminol) for the ultrasensitive detection of chloramphenicol

In this work, metal-organic frameworks (MOFs) are utilized as effective ECL coreactant accelerator to enhance the ECL responses of N-(aminobutyl)-N-(ethylisoluminol) (ABEI). Zn-based MOFs (MOF-Zn-1) were prepared by chelating Zn ions with melamine and thiophenedicarboxylic acid (TPDA), which observably accelerated the electrocatalytic oxidation of tripropylamine (TPA). Then, ABEI-MOF-Zn-1 as a high-performance ECL emitter was synthesized via an amide reaction between ABEI and mercaptopropionic acid (MPA) modified MOF-Zn-1. Strikingly, the ABEI-MOF-Zn-1 showed the 18-fold increase in the ECL signals relative to pure ABEI by using TPA as a coreactant. Moreover, ferrocene (Fc) as a quencher was first linked with capture DNA (cDNA), and then used to modify the ABEI-MOF-Zn-1, thereby constructing a label-free ECL biosensor. After the linkage between chloramphenicol (CAP) and aptamer DNA (aptDNA), the ECL response was definitely recovered by releasing L-DNA from double-stranded DNA (dsDNA, hybridization of aptDNA and L-DNA). The resultant sensor showed a wide linear range of 1.00 nM-0.10 mM (R² = 0.99) and a low limit of detection (LOD) down to 0.11 nM for detecting CAP. This work developed a novel pattern to design an efficient ECL enhanced emitter, coupled by expanding its potential applications in clinical diagnosis.