Piezopotential‐Driven Redox Reactions at the Surface of Piezoelectric Materials

Abstract

Piezocatalysis uses piezopotential to modulate charge carrier energetics (see picture), thus allowing the direct enhancement or suppression of electrochemical reactions that occur at a piezoelectric material/solution interface. Such a direct conversion of mechanical to chemical energy is shown by the electrochemical H2 evolution that is achieved by straining a piezoelectric material in aqueous medium.

Interface band structure engineering by ferroelectric polarization in perovskite solar cells

“…ZnO, GaN and CdS nanowires) to regulate charge seperation and collection, tune transport barrier height and adjust depletions regions in many electronic, photonic and optoelectric systems [32][33][34][35][36][37][38][39][40][41]. In addition to the piezotronic effect which describes the regulation of piezoelectric polarizations on the electrical transport properties, the recent piezophototronic effect has been suggested and proved to be able to effectively enhance/regulate the performance of photovoltaic device [32][33][34][35], optoelectronic light-emitting diodes [36,37], photodectors [38,39], and photocatalysis [40,41]. Given the fact that CH 3 NH 3 PbI 3 has been projected to be ferroelectric material, it is natural to consider that the polarization-induced electric field should play an important role in regulating the performance of perovskite solar cells.…”

Oxygen Reduction Reaction for Generating H2O2 through a Piezo‐Catalytic Process over Bismuth Oxychloride

“…[8] Moreover,t here are increasing research works reporting the directc onversion of mechanical energy into chemical energy,w hich is termed as the piezoelectrochemical effect [7] or piezo-catalytic effect. [9] In at ypical piezo-catalytic process, piezoelectric materials generate an electric field with external mechanical force, which can drive charge carriers (electrons and holes) participating in redox reactions such as water splitting [7,10] or elimination of pollutants. [9,11,12] Mechanistic analysis showedt hat H 2 O 2 could be generated in situ in the electrochemical process.…”

“…The as-generated electric field can induce and separate the electron-hole pairs, as shown in Equation (7). Then, protons and electrons interact with the O 2 C À to form H 2 O 2 ,a ss hown in Equation (10). Simultaneously,t he water will be transferred to OHC andH + by interacting with holes, as shown in Equation (9).…”

Coupling of piezoelectric effect with electrochemical processes

“…Recently there have been investigations into the use of dynamic applications, where a piezoelectric material is continuously and alternately strained between a tensile and compressive state resulting in a large and rapidly varying piezoelectric field within the material. This continuously varying system is prevented from achieving thermodynamic (electrochemical) equilibrium with its environment, the result of which is an enduring, though fluctuating, exchange of charge between the piezoelectric and its environment [6,7,29,30].…”

“…This phenomenon is known as the piezotronics effect [3][4][5]. One such heterojunction that is particularly dynamic is that which exists between a piezoelectric material and a chemical solution [6,7]. Piezoelectric fields have been used to control the corrosion rate of materials exposed to etchant solutions [8][9][10][11][12][13][14][15][16][17][18], selectively control the energetics and spatial separation of adsorbed [19,20] and photo-deposition materials [21][22][23][24][25][26][27][28], and have even been used to directly drive electrochemical reactions across piezoelectric/solution interface [6,7,[29][30][31].…”