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With rising CO2 emissions caused by the massive consumption of fossil fuels, it is highly desirable to develop strategies that adopt renewable energy to convert CO2 into value‐added chemical feedstocks. Over the past decades, photocatalytic reduction of CO2 using light energy has attracted considerable attention. However, the advanced photocatalysis techniques cannot exert their action where light is unavailable. Here, a method for CO2 reduction on basis of vibration‐driven piezoelectricity to yield a piezo‐electrocatalysis effect which requires mechanical vibration rather than light, is proposed. Under mild vibration and sacrificial agent‐free conditions, the piezoelectric BaTiO3 catalyst provides a suitable piezo‐potential to overcome the redox potential of CO2 and convert it into CO with a maximum yield of 63.3 µmol g−1, achieving a reactivity comparable to those of photocatalysts. The piezo‐electrocatalytic CO2 reduction reaction adds a new avenue in addition to the existing photocatalytic techniques by expanding the scope of energy utilization to promote carbon neutrality. [ABSTRACT FROM AUTHOR]

• The piezoelectric-catalysis of organic dye decomposition is realized in the BaTiO 3 /C hybrid nanocomposites. • The BaTiO 3 /C hybrid nanocomposites exhibits the higher catalytic activity than that of pure BaTiO 3. • The enhanced catalytic activity in BaTiO 3 /C hybrid nanocomposites can be ascribed to the improved charges separation. • The good recyclability makes BaTiO 3 /C potential in wastewater treatment through utilizing vibration energy. In this work, the strong piezocatalysis is found in the two-step hydrothermally-synthesized barium titanate/carbon hybrid nanocomposites and is used for rhodamine B dye decomposition. As the carbon content increases from 0 to 5 wt%, the catalytic performance of hybrid nanocomposites first increases and then slightly decreases. When the carbon content increases to 2 wt%, the barium titanate/carbon hybrid nanocomposites exhibit the optimal piezocatalytic performance, which have the ~75.5% dye decomposition ratio and the ~0.04901 min−1 reaction rate constant after the 40 min vibration stimulation, while that of the pure barium titanate are 48.4% and 0.01942 min−1, respectively. The improvement of piezocatalytic performance in barium titanate/carbon hybrid nanocomposites can be ascribed to the action of carbon's charge transfer which promotes the effective separation of the piezoelectrically-induced electric charges. After three runs recycle utilization tests, the barium titanate/carbon hybrid nanocomposites still exhibit ~70% decomposition ratio of rhodamine B dye. The strong piezocatalytic performance and the good reusability make the barium titanate/carbon hybrid nanocomposites potential in the field of wastewater treatment through utilizing natural vibration energy in future. [ABSTRACT FROM AUTHOR]

Abstract In this work, an obvious enhancement of pyroelectrically-driven catalytic activity is found in BaTiO 3 @ZnO heterostructures synthesized hydrothermally and then calcined. The pure BaTiO 3 is able to decompose up to 45% of the RhB dye in aqueous solution (5 mg/L) under 30–54 °C cold-hot cycle. As the ZnO content coating on the surface of the BaTiO 3 nanofibers is increased from 0 to 5 wt%, the decomposition ratio of the BaTiO 3 @ZnO heterostructures for RhB dye in aqueous solution first increases and then decreases, giving a maximum value of 97% at 2.5 wt%. The kinetic rate constant (K = 0.06384 cycle−1) of the catalytic reaction for BaTiO 3 @2.5%ZnO is 4 times higher than that of pure BaTiO 3. The enhancement of catalytic activity of BaTiO 3 @ZnO may be due to the formation of a semiconductor junction in which the electric field effectively separating the pyro-induced electron-hole pairs and further accelerates carrier migration. The ferroelectric heterostructures of BaTiO 3 @ZnO show pyroelectrically-driven-catalysis and may hold potential for use in decomposing dye wastewater through harvesting cold-hot alternation thermal-energy. [ABSTRACT FROM AUTHOR]

The piezo-electro-chemical effect, a phenomenon of vibration exciting chemical reaction, is hopeful for application in vibration-catalysis. In this work, BaTiO 3 nanofibers were synthesized through an electrospinning method combined with a conventional sol-gel process. The piezo-electro-chemical effect of BaTiO 3 nanofibers is realized through utilizing the product of piezoelectric effect and electro-chemical redox effect. BaTiO 3 nanofibers behave a high vibration-catalytic decomposition efficiency of 97.5% for Rhodamine B dye within 60 min vibration. The piezo-electro-chemical intermediate product OH was observed in the vibration-catalytic process. The piezo-electro-chemical effect of BaTiO 3 nanofibers is potential in utilizing vibration energy for dye wastewater treatment. [ABSTRACT FROM AUTHOR]