The highly crystalline mesoporous B/N co-doped TiO2 nanomaterial is successfully synthetized using a facile process. A modified polysulfide redox couple, (CH3)(4)N)(2)S/((CH3)(4)N)(2)Sn, was employed in CdS quantum dots (QDs) sensitized B/N co-doped TiO2 solar cell with ZnS passivation layers and NiS as counter electrode, followed by chemical bath deposition (CBD) in an organic solution to prepare the QDs-cell to ensure high wettability and superior penetration ability of the B/N co-doped TiO2 films, then obtained an open-circuit photovoltage of 1.23 V, a high ff of 89%, a short-circuit photocurrent (J(sc)) of 4.46 mA cm (2), and yielding a high overall energy conversion of 4.88%. (C) 2015 Elsevier Ltd. All rights reserved.