Band Position‐Independent Piezo‐Electrocatalysis for Ultrahigh CO₂ Conversion

Abstract

Piezo‐electrocatalysis as an emerging mechano‐to‐chemistry energy conversion technique opens multiple innovative opportunities and draws great interest over the past decade. However, the two potential mechanisms in piezo‐electrocatalysis, i.e., screening charge effect and energy band theory, generally coexist in the most piezoelectrics, making the essential mechanism remain controversial. Here, for the first time, the two mechanisms in piezo‐electrocatalytic CO2 reduction reaction (PECRR) is distinguished through a narrow‐bandgap piezo‐electrocatalyst strategy using MoS2 nanoflakes as demo. With conduction band of −0.12 eV, the MoS2 nanoflakes are unsatisfied for CO2‐to‐CO redox potential of −0.53 eV, yet they achieve an ultrahigh CO yield of ≈543.1 µmol g−1 h−1 in PECRR. Potential band position shifts under vibration are still unsatisfied with CO2‐to‐CO potential verified by theoretical investigation and piezo‐photocatalytic experiment, further indicating that the mechanism of piezo‐electrocatalysis is independent of band position. Besides, MoS2 nanoflakes exhibit unexpected intense “breathing” effect under vibration and enable the naked‐eye‐visible inhalation of CO2 gas, independently achieving the complete carbon cycle chain from CO2 capture to conversion. The CO2 inhalation and conversion processes in PECRR are revealed by a self‐designed in situ reaction cell. This work brings new insights into the essential mechanism and surface reaction evolution of piezo‐electrocatalysis.

Doping Engineering to Modulate Lattice and Electronic Structure for Enhanced Piezocatalytic Therapy and Ferroptosis

“…In general, the suitable energy band structure is the prerequisite for ROS generation in traditional SDT, i.e., a more negative conduction band than the redox potential of O 2 /·O 2 − to generate ·O 2 − , or a more positive valence band than H 2 O/·OH potential to produce ·OH. [ 10 ] In contrast, the energy band of piezoelectric materials can be tilted due to the formation of piezoelectric field under external stress, satisfying the requirement band level to generate ROS. [ 11 ] In recent years, several piezoelectric sonosensitizers such as BaTiO 3 , MoWO x , ZnO, and 2D Bi‐based materials have been reported for use in cancer therapy.…”

A novel 1D/2D core/shell CdS@SnS2 heterostructure for efficient piezocatalytic hydrogen evolution and pollutant degradation

“…6 Therefore, a series of piezocatalytic materials with asymmetric centers have been reported for applications in pollutant degradation, water splitting into hydrogen and carbon dioxide reduction. [7][8][9][10][11][12] Among them, typical piezocatalysts include BaTiO 3 , 13 ZnO, 14 Bi 2 Fe 4 O 9 , 15 MoS 2 , 16 and NaNbO 3 . 17 Unfortunately, although there are many kinds of piezocatalysts, single-component piezocatalysts inevitably have the problem of a high carrier recombination rate, which makes the performance of piezocatalysts unsatisfactory.…”

Piezocatalysis: a promising alternative route for CO2 reduction

“…Recently, some piezoelectric materials are reported to efficiently induce the CO 2 RR upon exposure to external mechanical energy (piezocatalytic). [28][29][30] Piezoelectric materials or piezoelectrics are the materials that can create electrical energy when mechanically stressed. 31 The piezocatalytic CO 2 RR has unique advantages over thermo-, photo-, and electrocatalytic routes.…”