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

Abstract 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 (MoS 2 ) 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 MoS 2 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 MoS 2 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.