Considering that conventional hydrothermal route to prepare photocatalysts is energy-consumable and difficult to scale-up, herein, uniform bismuth oxide formate (BiOHCOO; BiOR) nanosheets were firstly prepared from solid-state chemical reaction by a facile room-temperature grinding method. Furthermore, since BiOR could only respond to UV light, thin-nanosheet-based flowerlike BiO (HCOO)(x)I1-x solid solutions were synthesized via a one-pot method by adding KI into the BiOR reaction mixture and continuously grinding for an additional duration. As compared with BiOR, the resulting solid solution with x = 0.57 possessed narrower band gap, optimal energy levels and higher surface areas, leading to much higher visible-light photocatalytic activity for multiple pollutants degradation including rhodamine B (RhB), malachite green (MG) and colorless bisphenol A (BPA). This work demonstrates an easily-handling and eco-friendly solid-state reaction route to solid solutions with excellent visible light photocatalytic activity. Good photocatalytic performance was also confirmed by electrochemical techniques. (C) 2019 Elsevier Inc. All rights reserved.