Controlled Microwave-assisted Synthesis of Black Phosphorus Quantum Dots Boosting PEDOT:PSS Field-effect Direct-current Generator Performance

doi:10.15541/jim20260019

Abstract

Abstract:

Black phosphorus quantum dots (BPQDs) have attracted considerable interest in the energy sector owing to their tunable bandgap and high charge carrier mobility. However, the controllable synthesis of high-quality BPQDs remains a significant challenge. This study proposes a facile, low-cost, and efficient microwave-assisted liquid-phase exfoliation strategy for synthesizing BPQDs and explores their application in enhancing field-effect direct-current generator (FENG) performance. By systematically adjusting microwave temperature, duration, and precursor/solvent ratio, the optimal parameters were identified as 150 ℃, 6 h, and 1 : 2. Under these conditions, high-quality BPQDs with an average size as small as 1.47 nm and uniform distribution were successfully prepared. Compared with conventional methods, this strategy shows notable advantages in production efficiency and structural integrity. Furthermore, the as-prepared BPQDs were incorporated with the conductive polymer PEDOT:PSS to form an active friction layer for FENG. Experimental results demonstrated that incorporating BPQDs significantly improved the device’s output performance, and the average peak current increased by 43.6% compared to the pure PEDOT:PSS-based device. It was also found that reducing BPQD size by raising synthesis temperature linearly enhances output voltage, current, and charge transfer rate, and the best performance was achieved at 150 ℃. The improvement is attributed to the excellent electrical properties of ultrasmall BPQDs and their high specific surface area, which promote interfacial polarization and charge storage. This study not only provides an efficient and green strategy for the controllable preparation of BPQDs but also, through their successful integration into flexible self-powered systems, demonstrates their broad application potential in the field of energy conversion.

Key words: black phosphorus quantum dot, microwave-assisted exfoliation method, size-controlled synthesis, field-effect direct-current generator

CLC Number:

TQ174

YU Junlong, JIANG Yin, GUO Jiangtao, YANG Peizhi, FENG Xiaobo. Controlled Microwave-assisted Synthesis of Black Phosphorus Quantum Dots Boosting PEDOT:PSS Field-effect Direct-current Generator Performance[J]. Journal of Inorganic Materials, 2026, 41(10): 1481-1488.

Figures/Tables 8

Fig. 1 (a) TEM images and (b) particle size distribution histograms of BPQDs synthesized at different temperatures

Fig. 2 Morphology and structural characterization of BPQDs (a) TEM image; (b) Magnified TEM image; (c) High resolution TEM images showing lattice fringes; (d) Lateral size distribution histogram measured from TEM images; (e) AFM topographic image; (f) Corresponding height profiles along the white line in (e); (g) Height (thickness) distribution histogram measured from AFM image. Colorful figures are available on website

Fig. 3 Structural and chemical characterization of bulk BP and BPQDs (a) Comparison of Raman spectra for bulk BP and BPQDs; (b) XPS full survey spectrum of BPQDs; (c) High-resolution XPS spectrum with peak deconvolution for the P2p region of BPQDs; (d) FT-IR spectrum of BPQDs

Fig. 4 Working principle and structure of the FENG device (a) Electrostatic charge region; (b) Band bending in the non-contact region; (c) Band bending in the contact region; (d) Energy band diagram of the entire BPQDs/PEDOT:PSS surface; (e) Schematic of dynamic electrostatic charge inducing carrier transport in the BPQDs/PEDOT:PSS layer, leading to electrical energy generation in the external circuit; (f) Energy band diagram of the entire BPQDs/PEDOT:PSS surface when the rubber friction layer contacts the FEP film

Fig. 5 Electrical characterization of devices (a) Effect of BPQDs on the electrical performance of the FENG; (b-d) Influence of BPQDs prepared at different temperatures on the FENG’s (b) voltage, (c) current, and (d) transferred charge

Fig. S1 TEM images of BPQDs under different microwave processing time (a) 1 h; (b) 2 h; (c) 3 h; (d) 4 h; (e) 5 h; (f) 6 h

Fig. S2 (a) TEM images and (b) particle size distribution histograms of BPQDs prepared with different ratios of black phosphorus precursors to anhydrous ethanol

Table S1 Comparison of the characteristics between BPQDs and MXene as nanofillers in PEDOT:PSS

Comparison dimension	Core filler	Filler characteristics	Composite films fabrication	Operating mode	Key advantages	Output performance	Outstanding mechanism	Ref.
BPQDs/ PEDOT:PSS	BPQDs	Zero-dimensional quantum dots (1.47 nm), Tunable size/ bandgap, strong quantum confinement effect	Solution mixing followed by spin-coating	Contact- separation mode	Linearly tunable performance and ultrasmall size with size-dependent charge transfer rate	Output voltage up to 800 V and 43.6% increase in average peak current	Establishing a “synthesis temperature-size- output performance” linear tunability: dominant role of quantum confinemen	This work
MXene/ PEDOT:PSS	MXene (Ti₃C₂T_x)	High conductivity, layered structure, large lateral size	Vacuum filtering	Contact- separation mode	Ultrahigh sensitivity, fast response, and device integration	Output voltage ~29.6 V (10 N)	Intimate interface facilitates charge transport for high-sensitivity sensing	[S1]
Graphene/ PEDOT:PSS	CVD graphene	2D monolayer, high conductivity, PEDOT:PSS- modified interface	Spin-coating	Contact- separation mode	High transparency, high flexibility, and versatile surface engineering	Output voltage of 52 V and current density of 2.4 µA/cm²	Enhanced electrode conductivity and work function for improved overall output	[S2]

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