Series of SnO2/g-C3N4 heterojunctions with face-to-face contact have been synthesized by a two-step process. The morphology and photocatalytic property can be adjusted by tailoring the content of g-C3N4 in the heterostructures. The heterojunctions present flower-like morphology and vary the size of flower with the increase of the g-C3N4 content. The 50% SnO2/g-C3N4 heterojunctions exhibit the best performances for photodegradation of rhodamine B under solar light, which is attributed to the effective interfacial contact between SnO2 and g-C3N4, leading to the increased charge transfer and prolonged charge-hole separation time. Moreover, SnO2/g-C3N4 heterojunctions possess excellent stability after 4 recycling runs, because the face-to-face contact interface provides a large contact area, thus forming a close combination of two phases and guaranteeing effective separation of photogenerated carriers. Furthermore, a possible photocatalytic mechanism is analyzed and it is demonstrated that the hydroxyl radical species play an important role for the photocatalytic activity. This research highlights the promising applications of SnO2/g-C3N4 heterojunctions photocatalysts in the field of water purification and environmental remediation. (C) 2018 The Society of Powder Technology Japan. Published by Elsevier B.V. and The Society of Powder Technology Japan. All rights reserved.