Coupling morphology control and surface I grafting for boosting the photocatalytic activity of Bi2O2[BO2(OH)] nanosheets

• Thin-layered Bi 2 O 2 [BO 2 (OH)] nanosheets with I - grafting on surface were prepared. • I - -grafted Bi 2 O 2 [BO 2 (OH)] thin nanosheets show largely enhanced photodegradation. • Thin-layer structure shortens the transport distance of photogenerated charges. • I - grafting further inhibit carrier recombination and promote photocatalytic activity. • It also exhibits superior degradation ability for a variety of high-concentration pollutants. Photocatalytic performance of semiconductors is currently limited by low solar light utilization, rapid charge recombination and limited reactive sites. Reducing the thickness of layered photocatalysts can shorten the charge transport distance to inhibit their recombination and provide more reactive sites. Surface ionic grafting can broaden the light absorption range and promote the separation efficiency of carriers. In this work, the surface iodine ion modified Bi 2 O 2 [BO 2 (OH)] nanosheets are synthesized by combining the surfactant-assisted hydrothermal method and room-temperature KI solution treatment route. These nanosheets show increased photoabsorption in visible region, enlarged specific surface area and promoted charge separation. Compared with the pristine Bi 2 O 2 [BO 2 (OH)], the surface I - modified Bi 2 O 2 [BO 2 (OH)] nanosheets exhibit substantially strengthened photocatalytic performance for degradation of BPA, which increases beyond 25 times. The total organic carbon content (TOC) test reveals that the mineralization process of BPA. Electron spin resonance (ESR) measurements disclose the radicals that play dominant role in the photocatalytic process and confirm their increased yield over I - modified Bi 2 O 2 [BO 2 (OH)] nanosheets. In addition, BiOB-S-I2 also shows universality for degradation of a variety of high-concentration pollutants, including rhodamine B, methyl orange, methylene blue, phenol, 2,4-dichlorophenol and tetracycline hydrochloride. This study may provide a combined strategy for exploring high-performance photocatalysts via microstructure control and surface ionic decoration.