Steering Photoelectrons Excited in Carbon Dots into Platinum Cluster Catalyst for Solar-Driven Hydrogen Production.

In composite photosynthetic systems, one most primary promise is to pursue the effect coupling among light harvesting, charge transfer, and catalytic kinetics. Herein, this study designs the reduced carbon dots (r-CDs) as both photon harvesters and photoelectron donors in combination with the platinum (Pt) clusters and fabricated the function-integrated r-CD/Pt photocatalyst through a photochemical route to control the anchoring of Pt clusters on r-CDs' surface for solar-driven hydrogen (H) generation. In the obtained r-CD/Pt composite, the r-CDs absorb solar photons and transform them into energetic electrons, which transfer to the Pt clusters with favorable charge separation for H evolution reaction (HER).

Constructing n-ZnO@Au heterogeneous nanorod arrays on p-Si substrate as efficient photocathode for water splitting.

Developing ingenious heterostructure photoelectrodes in photoelectrochemical (PEC) cells to both harvest more solar photons and steer desired charge separation flow is a prerequisite challenge for PEC water splitting. Herein a hierarchical p-Si/n-ZnO@Au heterostructure was constructed via large-area growth of one-dimensional (1D) ZnO nanorod arrays (NRAs) on p-Si substrate followed by decorating with Au nanoparticles (NPs), which exhibited remarkably improved photocathode activity for PEC water splitting relative to the bare Si and Si/ZnO NRAs photocathodes. In addition to structural superiorities of 1D NRAs, a series of dynamic contributions from complementary band-gap structure, p-n heterojunctions and Au plasmon towards photon harvesting and charge separation were demonstrated to ensure a well-steered collection of photoelectrons at the exposed ZnO nanorods and Au NPs, enabling substantially improved photocathode performance.

Enriching Photoelectrons via Three Transition Channels in Amino-Conjugated Carbon Quantum Dots to Boost Photocatalytic Hydrogen Generation.

Well-steered transport of photogenerated carriers in optoelectronic systems underlies many emerging solar conversion technologies, yet assessing the charge transition route in nanomaterials remains a challenge. Herein, we combine the photoinduced absorption, emission, and excitation properties in high luminescent carbon quantum dots (CQDs) with an amino-modified surface to identify the existence of three photoelectron transition channels, that is, near-band-edge transition, multiphoton active transition in CQDs, and transfer from amino groups to CQDs, and together they contribute to strong blue photoluminescence (PL) independent of the excitation wavelength. Moreover, the enriching electron reservoir via these three channels was demonstrated in a holes cleaning environment to efficiently trigger water splitting into hydrogen with excellent stability and recyclability.

Well-Steered Charge-Carrier Transfer in 3D Branched CuxO/ZnO@Au Heterostructures for Efficient Photocatalytic Hydrogen Evolution.

Multi-component hetero-nanostructures exhibit multifunctional properties or synergistic performance and are thus considered as attractive materials for energy conversion applications. There is a long-standing demand to construct more sophisticated heterostructures for steering charge-carrier flow in semiconductor systems. Herein we fabricate a large-scale quantity of three-dimensional (3D) branched CuxO/ZnO@Au heterostructure consisting of CuO nanowires (NWs) and grafted ZnO nanodisks (NDs) decorated with Au nanoparticles via sequential hierarchical assemblies.