Ultra‐fast Piezocatalysts Enabled By Interfacial Interaction of Reduced Graphene Oxide/MoS₂ Heterostructures

Abstract

The catalytic activity has been investigated in 2D materials, and the unique structural and electronic properties contribute to their success in conventional heterogeneous catalysis. Heterojunction‐based piezocatalysis has attracted increasing attention due to the band‐structure engineering and the enhanced charge carrier separation by prominent piezoelectric effect. However, the piezocatalytic behavior of van der Waals (vdW) heterostructures is still unknown, and the finite active sites, catalyst poisoning, and poor conductivity are challenges for developing good piezocatalysts. Herein, a reduced graphene oxide (rGO)‐MoS2 heterostructure is rationally designed to tackle these challenges. The heterostructure shows a record‐high piezocatalytic degradation rate of 1.40 × 102 L mol−1 s−1, which is 7.86 times higher than MoS2 nanosheets. Piezoresponse force microscope measurements and density functional theory calculation reveal that the coupling between semiconductive and piezoelectric properties in the vdW heterojunction is vital to break the metallic state screening effect at the MoS2 edge for keeping the piezoelectric potential. The dynamic charges generated by MoS2 and the fast charge transfer in rGO activate and maintain catalytically active sites for pollutant degradation with an ultra‐fast rate and good stability. The working mechanism opens new avenues for developing efficient catalysts significant to wastewater treatments and other applications.

NiFe2O4 Nanofibers with Surface Oxygen Vacancies for Piezo-Catalytic Hydrogen Peroxide Production

“…In recent years, in addition to photocatalysis and thermo-catalysis, vibration has become an easily accessible source of energy in life. The piezoelectric catalytic degradation of organic dyes by non-centrosymmetric ferroelectric materials is increasingly being studied. − Piezoelectric catalysis is the application of an external mechanical force to a piezoelectric catalyst, causing the separation of the force-generated electrons (e – ) and holes (h + ) to produce a piezoelectric potential. , Piezoelectric catalysis effectively compensates for the limited availability of photocatalysis in time and place, greatly improving the use of energy with greater controllability. , Some inorganic piezoelectric materials have been reported to be used to achieve piezoelectric catalytic degradation of pollutants, such as BaTiO 3 , ZnO, MoS 2 , NaNbO 3 , and Pb (Zr Ti) O 3 (PZT) . However, many of the reported catalysts have serious limitations in terms of degradation efficiency, material selection, and multifaceted applications.…”

Boosting Piezocatalytic Activity of Bi5Ti3FeO15/BiOCl Heterostructured Nanocomposites for Degrading Multiple Dyes and Antibiotics

“…In the past decade, many piezoelectric materials have been demonstrated as promising catalysts in environmental remediation, and significant progress has been achieved. − However, the catalytic efficiencies of the currently reported piezocatalysts need to be further improved to meet the demands of practical applications. The development of high-performance piezocatalysts is one of the key concerns in the piezocatalytic area.…”

“…The reported strategies for improving carriers’ activities are cocatalysts, defect engineering, constructing heterojunction, morphology regulation, and so on. ,, Defect engineering, especially oxygen vacancy, and constructing a heterojunction are two effective approaches for improving the activities of carriers, which have attracted increasing attention. The introduction of moderated oxygen vacancy into a catalyst can enhance carrier concentration and increase the absorption of oxygen and OH – for a catalyst, promoting the formation of radicals and thus improving the piezocatalytic activity. ,− Constructing a heterojunction by coupling two suitable semiconductors with a unique band structure can tune the carriers’ transfer pathway inside the composite and improve the separation efficiency, promoting the generation of radicals. ,, Therefore, by the synergy of the oxygen vacancy and heterojunction in a composite catalyst, the piezocatalytic activity is expected to be further enhanced.…”

Rational Modulation of Effective Mass Near Band Edge of Li2SnO3 to Increase Photogenerated Carrier Separation Ratio and Photocatalytic Performance

“…Photocatalysis is a promising green technology that harnesses the redox ability of photogenerated electrons and holes to purify wastewater. − The photocatalytic process involves three important steps, among which the separation of photogenerated electrons and holes is often the critical step. − Some strategies have been developed to enhance separation of photogenerated electrons and holes, such as the use of heterojunctions, , phase junctions, , cocatalyst loading, − and facet junctions. , For example, Type-II heterojunctions and Z-scheme models have been assembled from two semiconductors that have a staggered band structure configuration and different carrier transfer mechanisms to promote spatial separation and suppress the recombination of charge carriers. Spatially decoupled structures such as zero- or two-dimensional and core–shell structures have been constructed to promote chemical redox reactions at different active sites.…”