Tailoring the optoelectronic properties of eco‐friendly CuGaS₂/ZnSe core/shell quantum dots for boosted photoelectrochemical solar hydrogen production

Abstract

Low‐cost and high‐performance photoelectrochemical (PEC) hydrogen production based on eco‐friendly colloidal core/shell quantum dots (QDs) represents a newly developing solar technology toward carbon neutrality. Herein, we present the synthesis of a novel type of environment‐friendly CuGaS2 (CGS)/ZnSe core/shell QDs with shell thicknesses‐tunable optoelectronic properties. As compared to CGS bare QDs, the prepared CGS/ZnSe core/shell QDs show enhanced visible light absorbance, emerging photoluminescence emission, tunable exciton lifetime, and improved photo‐stability. As a proof‐of‐concept, these eco‐friendly CGS/ZnSe core/shell QDs were applied as light sensitizers in a solar‐driven PEC hydrogen production system, delivering a nearly six times higher photocurrent density and improved device durability with respect to that of CGS core QDs under standard one sun AM 1.5G illumination. Our findings imply that such eco‐friendly core/shell QDs with tailored optoelectronic properties hold great potential for future “green” QDs‐based solar energy technologies.

Ligand‐Engineered Quantum Dots Decorated Heterojunction Photoelectrodes for Self‐Biased Solar Water Splitting

“…[ 24 ] The optical bandgap for QDs is evaluated to be 2.27 eV by using the Tauc plot method (Figure S10d, Supporting Information). [ 25 ] UV photoelectron spectroscopy (UPS) of ZCIS DDT QDs exhibits a high (18.74 eV) and a low (1.82 eV) binding energy cut‐off (Figure S10, Supporting Information), confirming the Fermi level ( E f ) to be −4.29 eV versus vacuum level and the valence band (VB) maximum to be 1.82 eV below the E f . [ 10c,26 ] Accordingly, the VB maximum and conduction band (CB) minimum of ZCIS DDT QDs were calculated to be −6.11 and −3.84 eV versus vacuum level, that is, 1.67 and −0.60 V versus NHE potential.…”

Toward efficient hybrid solar cells comprising quantum dots and organic materials: progress, strategies, and perspectives

“…58,59 In addition, other promising ecofriendly QDs also hold great potential in photovoltaics, photodetectors, and photoelectrochemical cells. [60][61][62] On the other hand, high efficiency, long-term stability, and low cost all play the major role in the large-scale applications of emerging photovoltaics. With regard to the distinct merits of OSCs and QDSCs, hybrid strategy holds promising potential to be leveraged for a win-win situation, in which OSCs can further improve the performance and stability, while QDSCs can propel rapid progress in the power conversion efficiency.…”

Quantum Dots, Passivation Layer and Cocatalysts for Enhanced Photoelectrochemical Hydrogen Production

“…[27] Likewise, nowadays researchers have tried to apply surface passivation to their materials for increasing stability. [28][29][30] In most cases, though, it still showed insufficient efficiency for achieving commercialized goals due to low current density. Applying the electrocatalyst to QDs-sensitized semiconductors can accelerate reaction kinetics.…”