The success of palladium-based cocatalysts in enhancing piezocatalytic hydrogen evolution has prompted an exploration of broader applicability across different metallic systems. In this study, we extend the cocatalyst engineering strategy to platinum (Pt), a benchmark catalyst for proton reduction due to its low activation energy and high intrinsic activity. BiFeO₃/Pt (BFO/Pt) hybrids were synthesized via ultrasonic reduction of H₂PtCl₆, yielding well-dispersed Pt nanoparticles on BiFeO₃ nanosheets. Under identical experimental conditions—40 kHz ultrasonic frequency, 100 W power, and Na₂SO₃ as hole scavenger—the BFO/Pt catalyst achieved a hydrogen evolution rate of 7.5 mol h⁻¹ per 10 mg of catalyst, representing a 12.5-fold increase over pristine BiFeO₃. While this performance is lower than that of the optimal BFO/Pd system (11.4 mol h⁻¹), it still demonstrates a substantial enhancement, confirming the general effectiveness of cocatalyst integration in piezocatalysis. The results underscore that even with superior catalytic materials like Pt, performance remains contingent on precise parameter optimization, including facet control, domain size, and loading amount.
The comparison between Pd and Pt highlights both the potential and limitations of different cocatalysts. Although Pt exhibits the lowest theoretical overpotential for hydrogen evolution, its actual performance in the BFO/Pt system falls short of Pd’s. This discrepancy arises from multiple factors beyond intrinsic activity. First, Pt nanoparticles tend to aggregate more readily during synthesis, leading to larger average sizes and reduced surface area compared to Pd-NCs under similar conditions. Second, the interfacial charge transfer efficiency between BiFeO₃ and Pt may be less favorable due to differences in work function alignment and Schottky barrier height. Third, the Pt-BiFeO₃ interface might exhibit higher resistance to electron migration, as evidenced by EIS data showing larger semicircle radii compared to BFO/Pd-NCs. These findings suggest that while Pt offers excellent catalytic activity, its practical effectiveness in piezocatalysis is limited by interfacial compatibility and stability issues.
To investigate the influence of structural parameters, we prepared a series of BFO/Pt samples with varying Pt domain sizes using controlled capping agents. The hydrogen evolution rate followed a volcano-shaped trend: increasing from 3.1 mol h⁻¹ (6 nm) to a maximum of 7.5 mol h⁻¹ (14 nm), then declining to 4.2 mol h⁻¹ (23 nm). This pattern mirrors that observed in Pd systems, indicating that the optimal domain size is a universal feature linked to charge transfer dynamics. PL quenching measurements confirm that the highest degree of charge separation occurs at 14 nm, aligning with peak catalytic activity. Similarly, polarization curves show that the current density and onset potential improve with optimal Pt size, further validating the importance of domain engineering. Loading amount studies reveal a similar trend: the rate peaks at 4.8 wt% Pt before decreasing due to site blocking and mechanical hindrance.
Importantly, the absence of light-shielding effects in piezocatalysis allows for higher metal loadings without compromising performance—a distinct advantage over photocatalytic systems.375815-87-5 supplier However, excessive loading still reduces efficiency by impeding lattice deformation and limiting strain-induced piezopotential generation.3650-09-7 InChIKey Moreover, XPS and TEM analyses after cycling confirm no significant degradation or leaching of Pt, indicating strong interfacial adhesion and robustness under operational conditions.PMID:28846230 These observations reinforce the conclusion that the primary limitation lies not in material instability but in interfacial and kinetic barriers.
This study confirms that cocatalyst engineering is a universally applicable strategy across various metals in piezocatalysis. While Pt offers superior intrinsic activity, its performance is constrained by synthesis-related aggregation and interfacial inefficiencies. In contrast, Pd achieves better overall results due to superior dispersion, favorable band alignment, and enhanced charge transfer. These insights emphasize that maximizing piezocatalytic performance requires not only selecting highly active metals but also optimizing their nanostructure and interfacial design. Future research should focus on hybrid cocatalysts combining Pt with other elements (e.g., Pd-Pt alloys), core-shell architectures, and defect-engineered interfaces to synergistically enhance both catalytic activity and charge transport. Ultimately, such rational design principles will enable the development of next-generation piezocatalytic materials capable of efficient, scalable, and sustainable hydrogen production from ambient mechanical energy.MedChemExpress (MCE) offers a wide range of high-quality research chemicals and biochemicals (novel life-science reagents, reference compounds and natural compounds) for scientific use. We have professionally experienced and friendly staff to meet your needs. We are a competent and trustworthy partner for your research and scientific projects.Related websites: https://www.medchemexpress.com