Improving the utilization efficiency of visible sunlight and improving the separation efficiency of photogenerated carriers are two important factors that enhance the catalytic activity of a photocatalyst. In this article, a tubular-hexagonal beta (β)-In₂S₃/In₂O₃ heterojunction with a porous shell encapsulated by N-doped carbon was prepared under a controlled sulfidation before the annealing treatment. This progressive synthetic strategy causes the In₂O₃ to be formed in situ on the In₂S₃ to guarantee their intimate contact. This material shows high efficiency, good recyclability and excellent functional-group tolerability towards photocatalyzing the coupling of amines to imines. Experimental and density functional theory studies have verified that its highly enhanced photocatalytic performances are ascribed to its unique structural features. The synergistic effect of the β-In₂S₃/In₂O₃ heterojunction with a tubular porous structure can enhance the absorption efficiency of broadband visible-sunlight. Upon being additionally coated with N-doped carbon, the intimately connected β-In₂S₃/In₂O₃ interfaces can further improve the separation efficiency of photogenerated carriers.