Manipulating Hetero-Nanowire Films for Flexible and Multifunctional Thermoelectric Devices.

Flexible thermoelectric devices hold significant promise in wearable electronics owing to their capacity for green energy generation, temperature sensing, and comfortable wear. However, the simultaneous achievement of excellent multifunctional sensing and power generation poses a challenge in these devices. Here, ordered tellurium-based hetero-nanowire films are designed for flexible and multifunctional thermoelectric devices by optimizing the Seebeck coefficient and power factor. The obtained devices can efficiently detect both object and environment temperature, thermal conductivity, heat proximity, and airflow. In addition, combining the thermoelectric units with radiative cooling materials exhibits remarkable thermal management capabilities, preventing device overheating and avoiding degradation in power generation. Impressively, this multifunctional electronics exhibits excellent resistance in extreme low earth orbit environments. The fabrication of such thermoelectric devices provides innovative insights into multimodal sensing and energy harvesting.

Biomimetic Multimodal Receptors for Comprehensive Artificial Human Somatosensory System.

Electronic skin (e-skin) capable of acquiring environmental and physiological information has attracted interest for healthcare, robotics, and human-machine interaction. However, traditional 2D e-skin only allows for in-plane force sensing, which limits access to comprehensive stimulus feedback due to the lack of out-of-plane signal detection caused by its 3D structure. Here, a dimension-switchable bioinspired receptor is reported to achieve multimodal perception by exploiting film kirigami. It offers the detection of in-plane (pressure and bending) and out-of-plane (force and airflow) signals by dynamically inducing the opening and reclosing of sensing unit. The receptor's hygroscopic and thermoelectric properties enable the sensing of humidity and temperature. Meanwhile, the thermoelectric receptor can differentiate mechanical stimuli from temperature by the voltage. The development enables a wide range of sensory capabilities of traditional e-skin and expands the applications in real life.

MOF-derived S-doped NiCo2O4 hollow cubic nanocage for highly efficient electrocatalytic oxygen evolution.

Inducing the surface reconstruction of spinels is critical for improving the electrocatalytic oxygen evolution reaction (OER) activity. Herein, S-doped NiCo2O4 hollow cubic nanocage was synthesized by anion etching Metal-Organic Frameworks (MOFs) template and air annealing strategies. The hollow structure possesses a large specific surface area and pore size, facilitating active site exposure and mass transport. S2- doping regulates the electronic structure, reducing the oxidation potential of Ni sites during the OER process, thus promoting the surface reconstruction into γ-NiOOH active species. Meanwhile, S2- doping enhances conductivity, accelerating interfacial charge transfer. As a result, S-NiCo2O4-6 exhibits superior OER activity (262 mV overpotential @ 10 mA cm-2) and stability in 1.0 M KOH solution. Furthermore, 20 % Pt/C‖S-NiCo2O4-6 only needs 1.832 V to achieve 50 mA (the electrochemical active area is 4 cm2) in a homemade anion exchange membrane (AEM) electrolyzer. This work proposes a novel approach for preparing efficient anion-doped spinel-based OER electrocatalysts.

Study on total residual oxidant decay in long-distance seawater intake pipeline of cooling system.

Electrochlorination is often used for biofouling control along the water intake pipeline of seawater cooling system, but with the increasing of pipeline length, this process needs to be further improved. In this study, the dynamic circulation and field pilot test were used to simulate the long-distance seawater intake pipeline, investigating total residual oxidant (TRO) decay and its influencing factors by comparing the bench test. The results showed that intermediate dosing could increase terminal TRO, but also reduce the CT value, resulting in decline of local inactivation effect. The initial concentration of dynamic cycle test was higher than that of bench test under the same terminal TRO, and the difference value between the two was affected by holding time. When the initial concentration was greater than 8.5 mg L-1, TRO decay rate was proportional to the seawater flow rate and inversely proportional to the initial concentration. The initial concentration of 8.5-10 mg L-1 could meet TRO decay requirement under 3 h holding time, and the dosing concentration could be reduced to 6 mg L-1 when the temperature was low. The results provided important guidance for the actual operation of biofouling control in long-distance water intake pipelines of cooling system.

Electrogenerated oxychlorides induced overlooked negative effects on electro-oxidation wastewater treatment in terms of over-evaluated COD removal efficiency and biotoxicity.

The high-efficiency and environmentally-friendly electro-oxidation (EO) would lose its competitive edge because of the production of oxychloride by-products (ClOx-), which has not yet drawn significant attention in academic and engineering communities. In this study, the negative effects of the electrogenerated ClOx- were compared among four commonly used anode materials (BDD, Ti4O7, PbO2 and Ru-IrO2) in terms of ClOx- interference on the evaluation of electrochemical COD removal performance and biotoxicity. Apparently, the COD removal performance of various EO systems were highly enhanced with increasing current density in the presence of Cl-, e.g., the amounts of COD removed by various EO systems from the phenol solution with an initial COD content of 280 mg L-1 at 40 mA cm-2 within 120 min decreased in the order: Ti4O7 of 265 mg L-1 > BDD of 257 mg L-1 > PbO2 of 202 mg L-1 > Ru-IrO2 of 118 mg L-1, which was different from the case with the absence of Cl- (BDD of 200 mg L-1 > Ti4O7 of 112 mg L-1 > PbO2 of 108 mg L-1 > Ru-IrO2 of 80 mg L-1) and the results after removing ClOx- by anoxic sulfite-based method (BDD of 205 mg L-1 > Ti4O7 of 160 mg L-1 > PbO2 of 153 mg L-1 > Ru-IrO2 of 99 mg L-1). These results can be ascribed to the ClOx- interference on COD evaluation, the extent of which decreased in the order: ClO3- > ClO- (where ClO4- cannot impact COD test). The highest overrated electrochemical COD removal performance of Ti4O7 may be associated with its relatively high production of ClO3- and the low mineralization extent. The chlorella inhibition ratio of ClOx- decreased in the order: ClO- > ClO3- >> ClO4-, which accounted for the biotoxicity increasement of the treated water (PbO2 68%, Ti4O7 56%, BDD 53%, Ru-IrO2 25%). Generally, the inevitable problems of overrated electrochemical COD removal performance and biotoxicity increasement induced by ClOx- should deserve significant attention and effective countermeasures should be also developed when employing EO process for wastewater treatment.

Robust electrolysis system divided by bipolar electrode and non-conductive membrane for energy-efficient calcium hardness removal.

In this study, an energy-efficient divided bipolar electrolysis system was developed for water softening, where two PTFE membranes were used as the separating materials and a bipolar electrode was employed to enhance the H2O-splitting reactions. As compared with other two operation modes, the optimum calcium harness removal efficiencies of 85% and 57% could be reached in the induction cathode effluent and terminal effluent, respectively, at 8 mA cm-2 in the mode A. Increasing the current density from 5 to 20 mA cm-2 evidently promoted the removal of calcium hardness from 33% to 65% in the terminal effluent and the CaCO3 precipitation rate from 743 to 1462 gCaCO3 h-1 m-2 with the increased energy consumption from 0.53 to 2.2 kWh kg-1CaCO3. The optimized Ca2+/HCO3- molar ratio was 1:1.2 for the calcium hardness removal. In addition, increasing the flow rate into each cathode chamber from 10 to 40 mL min-1 gradually decreased from 67% to 35%. The calcium hardness was mainly removed in the forms of vaterite and calcite in the alkaline effluents and was marginally precipitated as aragonite and calcite on the cathodes surface. Generally, present energy-efficient electrochemical water softening system showed great potential for application in industrial processes.

Differentiating the reaction mechanism of three-dimensionally electrocatalytic system packed with different particle electrodes: Electro-oxidation versus electro-fenton.

Recently, there are still some controversial mechanisms of the 3D electrocatalytic oxidation system, which would probably confound its industrial application. From the conventional viewpoint, the Ti4O7 material may be the desired particle electrodes in the 3D system since its high oxygen evolution potential favors the production of •OH via H2O splitting reaction at the anode side of Ti4O7 particle electrodes. In fact, the incorporation of Ti4O7 particles showed phenol degradation of 88% and COD removal of 51% within 120 min, under the optimum conditions at energy consumption of 0.668 kWh g-1 COD, the performance of which was much lower than those in many previous literatures. In contrast, the prepared carbon black-polytetrafluoroethylene composite (CB-PTFE) particles with abundant oxygen-containing functional groups could yield considerable amounts of H2O2 (200 mg L-1) in the 3D reactor and achieved a complete degradation of phenol and COD removal of 80% in the presence of Fe2+, accompanying a low energy consumption of only 0.080 kWh g-1 COD. It was estimated that only 20% of Ti4O7 particles near the anode attained the potential over 2.73 V/SCE at 30 mA cm-2 based on the potential test and simulation, responsible for the low yield of •OH via the H2O splitting on Ti4O7 (1.74 × 10-14 M), and the main role of Ti4O7 particle electrodes in phenol degradation was through direct oxidation. For the CB-PTFE-based 3D system, current density of 10 mA cm-2 was sufficient for all the CB-PTFE particles to attain cathodic potential of -0.67 V/SCE, conducive to the high yield of H2O2 and •OH (9.11 × 10-14 M) in the presence of Fe2+, and the •OH-mediated indirect oxidation was mainly responsible for the phenol degradation. Generally, this study can provide a deep insight into the 3D electrocatalytic oxidation technology and help to develop the high-efficiency and cost-efficient 3D technologies for industrial application.

The redox behavior of uranium on Beishan granite: Effect of Fe2+ and Fe3+ content.

The Beishan granitic area in Gansu Province is a site with the greatest potential for a repository of high-level radioactive waste (HLW) in China. In this study, the redox behavior of uranium on Beishan granite was investigated at pH values from ~4.4 to ~9.2. Due to the presence of Fe2+-containing fluorannite, results showed that U(VI) was partially reduced by the granites from boreholes 2 (486 m) and 28 (670 m) at a relatively low initial pH whether Na2CO3/NaCl or native groundwater was used as a background electrolyte. Partial oxidation of UO2 was observed when UO2 contacted Beishan granite directly. Therefore, this incomplete reduction of U(VI) was mainly attributed to minor Fe3+ that was either originally contained in the granite or generated during U(VI) reduction. Consequently, aliovalent oxides (e.g., U3O8, U3O7, U4O9, etc.) should be the thermodynamically stable phase in Beishan granite. A mechanism involving the dissolution of Fe2+ from the granite structure followed by interfacial adsorption/reaction was proposed for the U(VI) reduction. This study demonstrates that Beishan granite has a good reducing capacity, which is suitable for the immobilization of redox-sensitive radionuclides. However, potential oxidation of spent fuel by Fe3+ in the granite should also been taken into account.

Computational Analysis of the Interaction Energies between Amino Acid Residues of the Measles Virus Hemagglutinin and Its Receptors.

Measles virus (MV) causes an acute and highly devastating contagious disease in humans. Employing the crystal structures of three human receptors, signaling lymphocyte-activation molecule (SLAM), CD46, and Nectin-4, in complex with the measles virus hemagglutinin (MVH), we elucidated computationally the details of binding energies between the amino acid residues of MVH and those of the receptors with an ab initio fragment molecular orbital (FMO) method. The calculated inter-fragment interaction energies (IFIEs) revealed a number of significantly interacting amino acid residues of MVH that played essential roles in binding to the receptors. As predicted from previously reported experiments, some important amino-acid residues of MVH were shown to be common but others were specific to interactions with the three receptors. Particularly, some of the (non-polar) hydrophobic residues of MVH were found to be attractively interacting with multiple receptors, thus indicating the importance of the hydrophobic pocket for intermolecular interactions (especially in the case of Nectin-4). In contrast, the electrostatic interactions tended to be used for specific molecular recognition. Furthermore, we carried out FMO calculations for in silico experiments of amino acid mutations, finding reasonable agreements with virological experiments concerning the substitution effect of residues. Thus, the present study demonstrates that the electron-correlated FMO method is a powerful tool to search exhaustively for amino acid residues that contribute to interactions with receptor molecules. It is also applicable for designing inhibitors of MVH and engineered MVs for cancer therapy.