High Performance Generation of H₂O₂ under Piezophototronic Effect with Multi‐Layer In₂S₃ Nanosheets Modified by Spherical ZnS and BaTiO₃ Nanopiezoelectrics

Abstract

Manipulating the separation and transportation of photoexcited charge carriers in photoresponsive semiconductors via the piezoelectric polarization effect is an emerging strategy in the field of artificial photosynthesis. However, existing semiconductor photocatalysts, both with a wide range absorption for visible light and superior piezoelectricity are very scarce, leading to a low reactivity of photocatalysis. Here, a multi‐layer In2S3 nanosheet modified with spherical ZnS and BaTiO3 nanopiezoelectrics (ZnS/In2S3/BTO) is reported, generating approximately 378 µm of H2O2 in 100 min (and the concentration is still increasing) under co‐irradiation of visible light and ultrasound (piezophotocatalysis) in ethanol–water solution; this concentration is higher compared with two phases piezoelectric heterostructures (i.e., ZnS/BTO, In2S3/BTO, and ZnS/In2S3) and pure compounds (i.e., ZnS, In2S3, and BTO), and also higher than that of independent piezo‐ (≈254 µm) and photocatalysis (≈120 µm). Moreover, the concentration of H2O2 generated on ZnS/In2S3/BTO can be as high as approximately 1160 µm in 5 h of piezophotoreaction after experiencing six cycles of visible light concurrent with ultrasound irradiation. The enhancement of H2O2 yield on ZnS/In2S3/BTO in piezophotocatalysis can be attributed to the piezopotential‐induced internal electric polarization field promoting the separation of photoexcited charge carriers, thus boosting the rate of surface photoreaction.

Modulating the Molecular Structure of Graphitic Carbon Nitride for Identifying the Impact of the Piezoelectric Effect on Photocatalytic H2O2 Production

“…Therefore, piezoresponse force microscopy (PFM) was used to further characterize the piezoelectric properties of CN, CN-P, CN-OF, and CN-CA. It is well known that piezoelectric materials will deform under an applied electric field, which can be reflected by the amplitude signal of the PFM model. , Figure a–d shows that the amplitude signals were observed in CN, CN-P, CN-OF, and CN-CA, demonstrating the presence of piezoelectric response in all materials. Through phase analysis of the material, the relaxation of the piezoelectric domain polarization can be clearly observed, indicating that CN, CN-P, CN-OF, and CN-CA all have piezoelectric properties.…”

Efficient Production of Solar Hydrogen Peroxide Using Piezoelectric Polarization and Photoinduced Charge Transfer of Nanopiezoelectrics Sensitized by Carbon Quantum Dots

“…The working principle of piezophotocatalysis for the H 2 O 2 generation with BaTiO 3 :Nb modified by CDs is illus- S18a, Supporting Information) and ethanol to acetaldehyde (C 2 H 4 O). [15] Due to the metallic character of CDs, photon absorption causes interband transitions either from a fully occupied band (B −1 ) to a partially occupied conduction band near to the Fermi level (E F ) or, alternatively, from a conduction band to the lowest unoccupied band (B 1 ), as shown on the right-hand side of Figure 6. H + will diffuse and adhere to the surface of BaTiO 3 :Nb, where they are reduced to H 2 with electrons from the conduction band.…”

“…Most recently, piezoelectrics have been used to catalyze redox reactions for water splitting, [ 12 ] organic synthesis, [ 13 ] dye degradation, [ 14 ] and H 2 O 2 production. [ 15 ] The typical piezocatalysts are noncentrosymmetric crystals, such as BaTiO 3 , [ 16 ] BiFeO 3 , [ 17 ] and ZnSnO 3 . [ 18 ] The reaction rates of piezocatalysis are still far from being sufficiently high.…”

Self‐Assembled LaFeO3/ZnFe2O4/La2O3 Ultracompact Hybrids with Enhanced Piezo‐Phototronic Effect for Oxygen Activation in Ambient Conditions

“…On the basis of the above analysis, we can boldly derive that the piezo‐photocatalytic H 2 O 2 generation over LFZ‐x originated from the dissolved oxygen reduction via a two‐electron transfer pathway. [ 38 ] However, an abnormal suppression effect for H 2 O 2 generation was intriguingly observed by adding a hole quenching agent (EDTA‐2Na) to the reaction system. In principle, water oxidation by holes to produce • OH for H 2 O 2 production is not preferred owing to the relative higher VB position of major LaFeO 3 and ZnFe 2 O 4 phases than the redox potential of • OH/H 2 O (Figure 3f).…”