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[Display omitted] • Floatable P-ZsZc was prepared by pre-seeding ZnO followed by hydrothermal treatment. • P-ZsZc shows an uplifted valence band and new covalent Zn-O-C bonds. • Combining ZnO with PU improves photo-corrosion by boosting the h+ mobility. • Scavenger experiments and ESR spin trap analysis revealed H 2 O 2 as the main ROS. • The P-ZsZc achieved up to ∼ 90% SMX removal in continuous flow experiments. A highly efficient rigid floatable photocatalyst was prepared by seeding ZnO in polyurethane (PU) and subsequent hydrothermal ZnO coating (P-ZsZc). Compared to pristine ZnO, granular P-ZsZc had an uplifted valence band (VB) and generated new covalent Zn-O-C bond between PU and ZnO, resulting in a significantly enhanced photocorrosion resistance by boosting the mobility of photoexcited holes. In addition, the VB of P-ZsZc was favorable for the in-situ oxygen evolution reaction (OER) and H 2 O 2 production. As a result, the P-ZsZc achieved ∼ 98% removal of sulfamethoxazole (SMX) within 2 h for 5 consecutive cycles. Moreover, the SMX removal rate and Zn(II) leaching remained at ∼ 0.036 min−1 and 0.17 mg L−1, respectively, even during the fifth cycle for 10 h. Furthermore, scavenger experiments and electron spin resonance (ESR) spin trap analysis revealed that the main photogenerated reactive oxygen species (ROS) was H 2 O 2. Floatable P-ZsZc showed constant SMX removal of ∼ 90% in continuous flow experiments (CFEs) for up to 10 h of operation. This study offers a new approach to prepare floatable rigid photocatalysts capable of in-situ oxygen and H 2 O 2 production to degrade organic pollutants. [ABSTRACT FROM AUTHOR]

• PSAC under UVC 365 irradiation exhibits higher production of O 2 • due to slower e−/h+ recombination than other light sources. • The O 2 • generation from oxygen vacancies associated Si1+ is detected by using EPR spin trapping. • A strong correlation between the content of oxygen vacancies and Si1+ in PSAC and photocatalysis was obtained. • The continuous-flow column of PSAC under UVA 365 irradiation had a > 16-fold longer life than that of the adsorption column. Herein, we discovered and reported oxygen vacancies in silicon oxycarbide containing granular palm shell activated carbon (Si-PSAC) as a photocatalyst under UV irradiation. A strong correlation between the atomic content of Si1+, oxygen vacancies and photocatalytic performance of Si-PSAC was obtained. Based on the electron paramagnetic resonance and photoluminescence analyses, Si-PSAC under UVA 365 irradiation exhibited a higher donor density, better charge transfer and lower electron-hole recombination than that under the other light sources, leading to a higher O 2 · production efficiency. Si-PSAC exhibited effective removal performance for various anionic dyes and endocrine-disrupting chemicals under UVA 365 irradiation. Continuous-flow column tests revealed the life span of Si-PSAC under UVA 365 irradiation was extended by more than 16-fold compared to adsorption column. Since the oxygen vacancies can be created from the naturally present Si in the biomass derived Si-PSAC during the activation, this unexpected discovery of O 2 · production can extend commercially-available Si-PSAC into the full-scale photocatalysis. Image, graphical abstract [ABSTRACT FROM AUTHOR]