D/A heterojunction photocatalysts interspersed onto biochar to couple photocatalysis and adsorption for visible light-responsive efficient removal of pollutants

Phenol has various applications in industry, due to its hazardousness, solubility, and volatility, it persists in water and poses a risk to human health. People are excited by the progress of photodegradation technology that facilitates water pollution treatment. The effect of side-chain engineering is proven to enhance photodegradation performance by improving optoelectronic properties. Therefore, here is a strategy that introduces functional groups to change the electron cloud density, achieving excellent optoelectronic properties evidenced by efficient exciton dissociation, separation, and fine-tuned energy level. Subsequently, by coupling of photocatalysis and adsorption, the donor/acceptor (D/A) heterojunction photocatalysts (PBDB-T: BTTIC-TT, PBDB-T: BTTIC-Ph) are designed via loading on coconut-shell carbon to process phenol. The results indicate that the champion photocatalyst PBDB-T: BTTIC-TT possesses superior optoelectronic properties, which can be attributed to the stronger electron-withdrawing ability of thieno[3,2- b ]thiophene than benzene. Consequently, the synergistic efficiency of adsorption and photocatalysis of phenol (10, 20 mg/L) are removed within 10 mins over 90 % which is still valid after twenty cycles. Surprisingly, a high concentration of phenol (100 mg/L) also exhibited excellent removal efficiency of over 80 % within 60 min.