ABSTRACT
Piezoelectric materials have recently demonstrated their potential applications in clean energy exploration and environmental remediation through triggering a number of catalytic reactions by harvesting waste vibrational energy in the environment. In this work, unique lead-free 0.7BiFeO3-0.3BaTiO3 (BF-BT) nanoparticles with tuned band structure were synthesized by the hydrothermal method for use as piezoelectric catalysts to generate hydrogen by splitting water; a high production rate of 1.322 mmol/g was achieved in 1 h, which is 10 times higher than the production rate of pure BiFeO3. Of particular interest, BF-BT particles attached to nickel mesh have the ability to degrade rhodamine B in flowing water, demonstrating their potential to treat polluted water by anchoring BF-BT in drains. Finally, we propose novel insight on the piezocatalytic mechanism, which is based on the internal electric field (the sum of the depolarization field and the screening charge field) that drives electron/hole separation and movement.
ABSTRACT
Here it was demonstrated that the decoration of gold (Au) with polyaniline is an effective approach in increasing its electrocatalytic reduction of CO2 to CO. The core-shell-structured gold-polyaniline (Au-PANI) nanocomposite delivered a CO2 -to-CO conversion efficiency of 85 % with a high current density of 11.6â mA cm-2 . The polyaniline shell facilitated CO2 adsorption, and the subsequent formation of reaction intermediates on the gold core contributed to the high efficiency observed.
ABSTRACT
A scalable method for the assembly of oriented bacterial cellulose (BC) films is presented based on using wrinkled thin silicone substrates of meter-square size as templates during biotechnological syntheses of BC. Control samples, including flat templated and template-free bacterial cellulose, along with the oriented BC, are morphologically characterized using scanning electron microscopy (SEM). Multiple functional properties including wettability, birefringence, mechanical strength, crystallinity, water retention, thermal stability, etc., are being characterized for the BC samples, where the wrinkling-induced in situ BC alignment not only significantly improved material mechanical properties (both strength and toughness) but also endowed unique material surface characteristics such as wettability, crystallinity, and thermal stability. Owing to the enhanced properties observed, potential applications of wrinkle templated BC in printing and cell culture are being demonstrated as a proof of concept, which renders their approach promising for various biomedical and packaging applications.
ABSTRACT
Freestanding flexible electrodes with high areal mass loading are required for the development of flexible high-performance lithium-ion batteries (LIBs). Currently they face the challenge of low mass loading due to the limited concentrations attainable in processable dispersions. Here, we report a simple low-temperature hydrothermal route to fabricate flexible layered molybdenum disulfide (MoS2)/reduced graphene oxide (MSG) films offering high areal capacity and good lithium storage performance. This is achieved using a self-assembly process facilitated by the use of liquid crystalline graphene oxide (LCGO) and commercial MoS2 powders at a low temperature of 70 °C. The amphiphilic properties of ultralarge LCGO nanosheets facilitates the processability of large-size MoS2 powders, which is otherwise nondispersible in water. The resultant film with an areal mass of 8.2 mg cm-2 delivers a high areal capacity of 5.80 mAh cm-2 (706 mAh g-1) at 0.1 A g-1. This simple method can be adapted to similar nondispersible commercial battery materials for films fabrication or production of more complicated constructs via advanced fabrication technologies.
