Platinum Cluster/Carbon Quantum Dots Derived Graphene Heterostructured Carbon Nanofibers for Efficient and Durable Solar‐Driven Electrochemical Hydrogen Evolution

Abstract

Among various types of clean energy sources, hydrogen is considered promising due to its high energy density, zero carbon emission during combustion. [4][5][6] To fully deploy technologies for hydrogen production, there is a critical need for the selection of efficient hydrogen evolution reaction (HER) catalysts. [7][8][9] Many researchers focus on producing cost-effective Pt-based catalysts by enhancing the active sites of the Pt (e.g., single atom-based catalysts) and distribution of the Pt in the supports, which can largely decrease the amount of Pt. [10][11][12][13] However, up to date, it is still a major challenge to stabilize Pt nanoclusters during the HER. [14,15] 1D or 2D nanostructures can have large surface energy, spatial confinement, and tunable imperfections, which endow them with unique properties, such as increased catalytic activity, enhanced mechanical strength, and chemical stability. [16][17][18][19] Combining 0D Pt nanocluster with 1D/2D nanostructures can prevent their aggregation and mass loss in catalytic recycling. [20] Until now, considerable efforts have focused on developing low-dimensional heterostructures. [21,22] Carbon nanofibers (CNFs) possess unique mechanical, thermal, and Large scale solar-driven hydrogen production is a crucial step toward decarbonizing society. However, the solar-to-hydrogen (STH) conversion efficiency, long-term stability, and cost-effectiveness in hydrogen evolution reaction (HER) still need to be improved. Herein, an efficient approach is demonstrated to produce low-dimensional Pt/graphene-carbon nanofibers (CNFs)-based heterostructures for bias-free, highly efficient, and durable HER. Carbon dots are used as efficient building blocks for the in situ formation of graphene along the CNFs surface. The presence of graphene enhances the electronic conductivity of CNFs to ≈3013.5 S m −1 and simultaneously supports the uniform Pt clusters growth and efficient electron transport during HER. The electrode with a low Pt loading amount (3.4 µg cm −2 ) exhibits a remarkable mass activity of HER in both acidic and alkaline media, which is significantly better than that of commercial Pt/C (31 µg cm −2 of Pt loading). In addition, using a luminescent solar concentrator-coupled solar cell to provide voltage, the bias-free water splitting system exhibits an STH efficiency of 0.22% upon one-sun illumination. These results are promising toward using low-dimensional heterostructured catalysts for future energy storage and conversion applications.The ORCID identification number(s) for the author(s) of this article can be found under https://doi.org/10.1002/smtd.202101470.

Dual-emission carbon dots for sensitive fluorescence detection of metal ions and ethanol in water

“…2a, the survey spectrum shows that there are three peaks at 284.08, 399.08 and 532.08 eV, indicating that the red CDs are composed of C, N and O elements and the atomic content ratio is 77.52%, 5.44% and 17.04%. 52 As shown in Fig. 2b, C 1s can be separated into three peaks at 284.88, 285.88 and 287.98 eV, corresponding to C–C/CC, C–N/C–O and CN, respectively.…”

Large scale synthesis of carbon dots for efficient luminescent solar concentrators

“…The large Stokes shift of 0.67 eV indicates that the C-dots prepared via a solvent-free reaction present a great potential for LSC application. 32,47 The QYs of the C-dots are among 18-65%, depending on the type of precursors used in the synthesis. For example, the Ca cation capped C-dots have the QYs of 65 AE 5% (CA/CaCl 2 ) and 57 AE 5% (CaCA), which are higher than those of C-dots produced by using CA (25%), NaCA (30%), MgCA (47%), FeCA (40%) and CuCA (18%).…”

Engineering Cu2O Nanowire Surfaces for Photoelectrochemical Hydrogen Evolution Reaction

“…Apart from its very low efficiency, the mechanism is one of the promising pathways for sustaining renewable hydrogen production. PEC devices use light-absorbing semiconductors that can absorb solar energy and perform water electrolysis. − It is challenging to obtain semiconductors that act as a catalyst for hydrogen evolution reaction (HER) and absorb light at the same time. In addition, both the water-splitting process and the light absorption have issues to be solved.…”