Beyond-1000 nm low-energy sunlight-driven photocatalysis enabled by quantum dot-based photon upconversion

Area of Science:

• Materials Science
• Photochemistry
• Sustainable Chemistry

Background:

• Solar energy conversion is crucial for green chemistry but limited by low-energy light absorption.
• Transformations beyond 1000 nm are challenging due to insufficient absorption and photon energy.

Purpose of the Study:

• To develop an efficient upconversion material for low-energy sunlight utilization.
• To enhance photocatalysis using near-infrared-II (NIR-II) light beyond 1000 nm.

Main Methods:

• Utilized lead sulfide quantum dots (PbS QDs) as NIR-II absorbers.
• Engineered the cadmium sulfide (CdS) shell to optimize triplet exciton transfer and lifetime.
• Incorporated rubrene as an annihilator for efficient energy upconversion.

Main Results:

• Achieved a record upconversion efficiency of 3.9% under 1064 nm excitation.
• Demonstrated unprecedented large-volume photocatalysis driven by light beyond 1000 nm.
• Successfully applied the system to free radical and atom transfer radical polymerization.

Conclusions:

• The hybrid photosensitizer significantly enhances solar energy utilization for chemical transformations.
• This work paves the way for advanced solar energy technologies, including next-generation photovoltaics and photocatalysis.