Free-standing and flexible 0D CeO2 nanodot/1D La(OH)3 nanofiber heterojunction net as a novel efficient and easily recyclable photocatalyst

Abstract

Compared to conventional semiconductor photocatalysts, 0D/1D heterojunction photocatalysts, emerging as an effective strategy to achieve charge mobility of photoinduced electron–hole pairs, have drawn considerable attention. Unfortunately, the nano-sized 0D/1D heterojunction normally suffers from poor recyclability and low photoactivity, which are not suitable for practical photocatalysis applications. Here, we report an unprecedented photocatalyst, denoted as a 0D CeO₂/1D La(OH)₃ heterojunction net, in which 0D CeO₂ nanodots are tightly anchored onto extra-long 1D La(OH)₃ nanofibers. The overwhelming photocatalytic capability of the as-prepared heterojunction was demonstrated by its decoloration of organic pollutants (Rhodamine B and methyl orange) and the reduction of hexavalent chromium under UV light irradiation. The boosted photocatalytic properties were ascribed to the enhanced optical absorption and fast charge transfer, as well as separation, which were induced by the synergistic effects of self-created in-built Ce⁴⁺/Ce³⁺ redox centers and the formation of heterojunctions between CeO₂ and La(OH)₃. More importantly, the unique net structure endows the 0D CeO₂/1D La(OH)₃ heterojunctions with excellent recyclability, which can address the challenges of a traditional nano-sized 0D/1D heterojunction. Our work paves a way toward constructing promising 0D/1D photocatalytic systems for the practical photocatalytic treatment of wastewater.