One-dimensional anodic titanium oxide (ATO) nanotube arrays hold great potential as photoanode for photoelectrochemical (PEC) water splitting. In this work, we report a facile and eco-friendly electrochemical hydrogenation method to modify the electronic and PEC properties of ATO nanotube films. The hydrogenated ATO (ATO-H) electrodes present a significantly improved photocurrent of 0.65 mA/cm² in comparison with that of pristine ATO nanotubes (0.29 mA/cm²) recorded under air mass 1.5 global illumination. The incident photon-to-current efficiency measurement suggests that the enhanced photocurrent of ATO-H nanotubes is mainly ascribed to the improved photoactivity in the UV region. We propose that the electrochemical hydrogenation induced surface oxygen vacancies contribute to the substantially enhanced electrical conductivity and photoactivity.

Charge-transfer based molecular conductors have attracted great attention in recent years, but have been rarely explored in the field of electromagnetic materials. In this work, a nanostructural tetrathiofulvlene-7,7,8,8-tetracyanoquinodimethane (TTF–TCNQ) complex, an organic charge-transfer system, was prepared via a solution mixing route. The electromagnetic response behavior of the TTF–TCNQ complex was systematically investigated. The results indicate that the TTF–TCNQ complex shows good electromagnetic absorption (EMA) performance with a filler-loading ratio of 30 wt% in the matrix, where its effective EMA bandwidth can be tuned in the frequency range of 7.1–16.6 GHz. Moreover, the TTF–TCNQ complex exhibits excellent electromagnetic interference shielding performance in the X-band when the filler-loading ratio increases to 45 wt%. A model involving an electronic structure, multi-polarization, and a conductive network is used to explain the electromagnetic response behavior of the TTF–TCNQ complex. This research opens up the exploration of organic charge-transfer systems in the field of electromagnetic materials, and significantly broadens the application scope of charge-transfer materials.

Anodic TiO2 nanotubes have been studied extensively for many years. However, the growth kinetics still remains unclear. The systematic study of the current transient under constant anodizing voltage has not been mentioned in the original literature. Here, a derivation and its corresponding theoretical formula are proposed to overcome this challenge. In this paper, the theoretical expressions for the time dependent ionic current and electronic current are derived to explore the anodizing process of Ti. The anodizing current-time curves under different anodizing voltages and different temperatures are experimentally investigated in the anodization of Ti. Furthermore, the quantitative relationship between the thickness of the barrier layer and anodizing time, and the relationships between the ionic/electronic current and temperatures are proposed in this paper. All of the current-transient plots can be fitted consistently by the proposed theoretical expressions. Additionally, it is the first time that the coefficient A of the exponential relationship (ionic current j(ion) = A exp(BE)) has been determined under various temperatures and voltages. And the results indicate that as temperature and voltage increase, ionic current and electronic current both increase. The temperature has a larger effect on electronic current than ionic current. These results can promote the research of kinetics from a qualitative to quantitative level.