Photocatalytic Hydrogen Evolution Enabled by Oriented Phase Interactions between Monolayers of P3HT-Wrapped MoS₂ and Ferroelectric Lamellar Crystals

Unveiled as a unique feature of polymer ferroelectric crystals, oriented coalescence within monolayers of poly(vinylidenefluoride-co-trifluoroethylene)(PVDF-TrFE) ferroelectric crystals has been found regulable upon monolayer roughness, which is accompanied by the adjustment of piezoelectric responses, and thus phase polarity. Simply with the deposition of poly(3-hexylthiophene (P3HT)-wrapped molybdenum disulfide (MoS₂) sheets, piezoelectric responses of polymer ferroelectric crystals are surprisingly enhanced further. Also dependent on the degrees of phase polarity, the binding energy of P3HT excitons declines to a level comparable to that of inorganic excitons, together with the alteration of work functions. These results suggest mutual polarization between ferroelectric lamellar crystals and originally nonpolar P3HT-wrapped MoS₂ sheets as a result of dipole-induced dipole phase interactions. As the Fermi levels and driving forces of interfacial electron transition are also adjustable upon involved phase interactions, P3HT-wrapped MoS₂ sheets can photocatalyze hydrogen evolution with an average production rate reaching 4.474 mmol g⁻¹ h⁻¹, which is 1.6 times higher than the results without the aid of phase interactions. Accordingly, amplifying phase interactions has been elucidated feasible, and able to serve as a promising approach to generally promote photocatalytic reactions.