A two-photon tandem black phosphorus quantum dot-sensitized BiVO4 photoanode for solar water splitting

• Published in: Energy & environmental science Vol. 15; no. 2; pp. 672 - 679
• Main Authors: Jin, Bingjun, Cho, Yoonjun, Park, Cheolwoo, Jeong, Jeehun, Kim, Sungsoon, Jin, Jie, Kim, Wooyul, Wang, Luyang, Lu, Siyu, Zhang, Shengli, Sang Ho Oh, Zhang, Kan, Park, Jong Hyeok
• Format: Journal Article
• Language: English
• Published: Cambridge Royal Society of Chemistry 01.01.2022
• Subjects: Bismuth oxides; Catalysts; Chemical evolution; Kinetics; Near infrared radiation; Oxidation; Phosphorus; Photoanodes; Photoelectric effect; Photon absorption; Photons; Quantum dots; Reaction kinetics; Recombination; Titanium dioxide; Vanadates; Water splitting
• ISSN: 1754-5692; 1754-5706
• DOI: 10.1039/d1ee03014k

The photoelectrochemical (PEC) water splitting efficiency is profoundly restricted by the limited light harvesting, rapid charge recombination, and sluggish water oxidation kinetics, in which the construction of a photoelectrode requires a strategic approach to overcome such intrinsic hurdles. Herein, we demonstrate novel black phosphorus quantum dots (BPQDs) with significant light absorbability up to the near-infrared region (NIR) to sensitize the etched BiVO4 photoanode (E-BiVO4) for a two-photon absorption tandem photoanode. A subsequent TiO2 overlayer (OL) significantly improves the stability of the E-BiVO4/BPQDs and eliminates the surface trap state to enhance charge separation. Finally, an oxygen evolution catalyst (OEC), NiOOH, loaded on E-BiVO4/BPQDs/OL further improves the water oxidation kinetics. The rationally designed E-BiVO4/BPQDs/OL-OEC with multiple components, each with definite functions, achieves a photocurrent density of 6.2 mA cm−2 at 1.23 V vs. reversible hydrogen electrode (RHE) under AM 1.5 illumination, offering a high-end standard approach for achieving efficient solar-to-fuel conversion devices by combining a photosensitizer and passivation layer.