Phosphate modified nanoarchitectonics for promoted photocatalytic singlet oxygen generation and carbamazepine degradation of (0 1 0) facet-exposed BiOCl

1 O 2 generation over (0   0   1) or (0   1   0) facet exposed BiOCl (B001 or B010) with/without phosphate modification were studied from the aspects of excitons involved energy transfer route, the O 2 − oxidation based charge transfer route and the H 2 O 2 oxidation by HClO. Phosphate modification not only enhance charge separation thus result in H 2 O 2 oxidation by HClO to release 1 O 2 but also weaken excitonic effect in the confined layer of BiOCl accordingly affect 1 O 2 generation via energy transfer. Considering [0   0   1] orientation favors the formation of excitons than that of [0   1   0] direction over BiOCl, excitons loss was hardly compensated by the H 2 O 2 oxidation by HClO for 1 O 2 generation over phosphate modified B001. Nevertheless, limited excitonic effect makes the O 2 − oxidation by h + via charge transfer as dominant route for 1 O 2 yielding over B010, the extra H 2 O 2 oxidation with HClO after phosphate modification significantly enhance 1 O 2 generation over B010 followed with 2.2 times higher carbamazepine photodegradation activity. The initial attack of C C bond via 1 O 2 to form epoxide played important roles on carbamazepine degradation. This study demonstrated that the facet-specific phosphate modification of photocatalysts can finely tune reactive 1 O 2 species for superior pharmaceuticals degradations.