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In this study, a facile strategy to promote electrochemical performance of free‐standing Li‐ion battery electrode composed of titanium dioxide (TiO2) via composite formation with reduced graphene oxide (RGO) using ultrafast and self‐expansion reduction reaction (USER) was proposed. This approach induced self‐expansion through rapid heating providing abundance of cavities/empty spaces to alleviate volume change during charge/discharge process resulting in boosted storage and conversion response of the system (765 mAh g−1 at 0.05 A g−1) and accelerated Coulombic efficiency. Detailed electrochemical, microscopic and structural analyses (ex‐situ) of the film prove that this internal expansion delivers enhanced ionic diffusion and shielding material from volume changes during charge/discharge process. Therefore, we believe that this simple and very fast strategy offers a venue to overcome one of the main bottleneck in promotion of electrochemical performance of other active materials which are sensitive to volume expansion during lithiation/delithiation process. [ABSTRACT FROM AUTHOR]

• Bifunctional composite photocatalyst based on mTiO 2 and ex-gCN was synthesized. • mTiO 2 _ex-gCN boosted two photocatalytic processes: RhB removal and H 2 evolution. • mTiO 2 _ex-gCN evolved 70 times higher amount of H 2 than pristine ex-gCN. • The improved photocatalytic property is due to synergic effect of both components. Here, we designed a molecular structure fabrication route based on spherical mesoporous TiO 2 and exfoliated graphitic carbon nitride (mTiO 2 _ex-gCN) by combining hard templating and hydrothermal methods. The mTiO 2 _ex-gCN boosted two photocatalytic processes: hydrogen evolution under simulated solar illumination and degradation of Rhodamine B (RhB) with the assistance of UV–vis and visible light irradiations. RhB degradation under UV–vis light was 2.94 and 1.39 times higher than ex-gCN and mTiO 2 , respectively. Additionally, dye degradation under visible light was enhanced by a 1.22 factor in respect to ex-gCN. However, a more spectacular performance was detected in the process of photocatalytic hydrogen evolution – the efficiency of the catalyst yielded a 70 times higher amount of H 2 in respect to ex-gCN. It is proposed that enhanced photocatalytic activity is due to synergy provided by individual counterparts, which tuned energy band gap, improved specific surface area, and enhanced ability to suppress the charge carrier recombination. [Display omitted] [ABSTRACT FROM AUTHOR]

Recently, to meet the growing demand for stable and flexible batteries, anodes in the form of thin films have drawn the attention of researchers. It is clear that mass production of such batteries would bring the worldwide distribution of flexible devices and wearable electronics closer. Currently, electrodes are deposited on a flexible substrate and consist of conductive and binding agents that increase the volume/weight of the electrode. Here, we propose free-standing and non-active-material-free thin films based on reduced graphene oxide (rGO), titanium dioxide (TiO2) and manganese dioxide (MnO2) as working electrodes in lithium-ion half-cells prepared via the vacuum-assisted filtration method. The electrochemical performance of the assembled half-cells exhibited good cyclic stability and a reversible capacity at lower current densities. The addition of TiO2 and MnO2 improved the capacity of the rGO film, while rGO itself provided a stable rate performance. rGO/TiO2/MnO2 film showed the highest discharge capacity (483 mAh/g at 50 mA/g). In addition, all assembled cells displayed excellent repeatability and reversibility in cyclic voltammetry measurements and good lithium-ion diffusion through the electrolyte, SEI layer and the active material itself. [ABSTRACT FROM AUTHOR]