Enhanced photocatalytic H2 evolution by plasmonic and piezotronic effects based on periodic Al/BaTiO3 heterostructures

Abstract

Plasmonic catalysis of solar water splitting has been extensively exploited these years for the fast-growing energy demands and environmental friendliness. However, most of the plasmonic systems are restricted on the noble metals and semiconductors, which limited the cost efficiency of the photocatalysts and further investigations of metal plasmons coupling with other research filed. Herein, we presented nonprecious Al@BaTiO3 (Al/BTO) plasmonic heterostructures on Ti foams for a synergistic piezo-photocatalytic water splitting and pollutant degradation. An impressive local surface plasmon resonance (LSPR) and solar energy harvesting ability (in the ultraviolet–visible light region) are achieved on the Al/BTO photoelectrode, which endow the heterostructure with an excellent solar H2 evolution (327 μmol h−1 cm−2) and 4-nitrophenol (4-NP) degradation rate. Furthermore, the BTO substrates upon magnetic field induced mechanical stimuli provide a strong polarization potential to the plasmonic catalyst by significantly enhancing the photo-generated carrier separation and transfer. The synergistic piezo-photocatalysis exhibited almost 50% increase in the H2 production (657 μmol h−1 cm−2) and decolourization of 4-NP, which is comparable to a traditional noble metallic plasmonic photoelectrode. The hybrid catalyst delivers a long-term durability in the cycling tests, maintaining ∼90% of the activity after 30 h. This work demonstrates that non-noble metallic plasmons and piezoelectronic effect can serve synchronously as highly active photocatalytic agents, which not only boost the solar energy conversion efficiency but also decrease the material cost.