Monitoring the length change of Ni@C composite electrodes during charging/discharging processes

In situ preparation of molybdenum-dioxide-incorporated carbonized silk fiber and its application in supercapacitors

A previous study found that the capacitive behavior of nanoparticles fed to the silkworm can be delivered to carbonized silk fibers, which can be used to fabricate electrodes for the construction of flexible supercapacitors. However, the tendency of nanoparticles to aggregate decreases the quantity of nanoparticles that enter the silk and therefore reduces the capacitance performance of the prepared carbonized silk. Here, we sprayed ammonium molybdate tetrahydrate (AMT) on the surface of mulberry leaves used for feeding silkworms and investigated the effect of feeding AMT on the growth of silkworms and the properties of spun silk. The precursor incorporated into the silk was converted into scattered MoO2 NPs, which were embedded within the carbonized silk fiber (CSF) via carbothermal reduction. The specific capacitance of CSF obtained from silkworms fed with an aqueous solution of AMT-treated mulberry leaves reached up to 298 F/g at 0.2 g/A, which is much higher than that of the control group (102 F/g). Since AMT is highly water-soluble, and its concentration can be easily modulated, we believe that the proposed strategy is feasible for the large-scale fabrication of CSF with enhanced capacitive performance.

Electrocatalyst Design for Conversion of Energy Molecules: Electronic State Modulation and Mass Transport Regulation

Electrocatalytic conversions of energy molecules are involved in many energy conversion processes. Improving the activity of electrocatalyst is critical for increasing the efficiency of these energy conversion processes. However, the...

A Simple Mechanical Method to Modulate the Electrochemical Electrosorption Processes at Metal Surfaces

The coupling of electrochemical processes and surface strain has been widely investigated in the past. The present work briefly introduces a simple method to modulate the electrochemical process at metal surfaces by mechanical bending. In this way, the static strain at the metal layer can reach the order of 1%. The cyclic voltammogram was used to study the electrosorption process of oxygen species at sputtered metal surfaces under different strain states. The experimental results show that the desorption peak potential of oxygen at the Au surface shifted positively by tensile strain, whereas the desorption peak potential at the Pt surface shifted negatively. This phenomenon indicates that tensile strain has an opposite effect on the electrosorption process for Au and Pt surfaces. Our results agree with the previous reports on the potential variation induced by dynamic strain. This work thus offers a simple method to modulate the electrosorption process at metal surfaces and then to enhance the reactivity of metal electrodes.