1D nanomaterial-based heterojunctions with unique structures and outstanding physicochemical properties are divided into several types including type II heterojunction, p–n type heterojunction, Schottky junction, Z-type heterojunction, and S-scheme heterojunction.

SiO ₂ , an insulator, hardly has any photocatalytic acitivity due to its intrinsic property, and it is generally used as a hard template to increase the surface area of catalysts.

A visible-light-sensitive Bi₂MoO₆–BiOCl heterojunction photocatalyst was synthesized via a hydrothermal process.

The photocatalytic activity enhancement of the ZnO/mpg-C₃N₄ is due to the high separation and easy transfer of photogenerated electron–hole pairs.