Highly regular laser-induced periodic silicon surface modified by MXene and ALD TiO2 for organic pollutants degradation

[Display omitted] •Highly regular laser-induced periodic Si structures covered by MXene and TiO2 were produced.•SiNR/MXene/TiO2 achieves 77% degradation of rhodamine 6G, 2.57x higher than SiNR/TiO2.•MXene enhances electron-hole pair separation, reduces resistivity in the heterostructure.•Light trapping effect in Si cavity covered by MXene/TiO2 increases optical absorption. The co-catalytic ability of surface groups in MXene renders MXene-based composites efficient photocatalysts for organic dye photodegradation. In this study, we introduce a novel approach combining highly-regular laser-induced periodic surface Si structures (Si nanoripples - SiNR) with MXene and TiO2, deposited through atomic layer deposition (ALD), to achieve stable, repeatable, and highly efficient photocatalytic materials. The ternary system, SiNR/MXene/TiO2, exhibits high light absorption across the entire spectrum. Furthermore, the photodegradation efficiency of SiNR/MXene/TiO2 is approximately 2.6 times higher than that of SiNR/TiO2 samples. This remarkable enhancement in photocatalytic activity can be attributed to two main factors: increased separation of photogenerated charge carriers and enhanced light absorbance through the light trapping effect. The synergistic combination of SiNRs, MXene, and TiO2 in the ternary nanocomposite structure enables efficient separation of photogenerated charge carriers, thereby minimizing recombination and enhancing the degradation of organic dyes. Moreover, the introduction of a laser-patterned surface and its ALD modification significantly enhances light absorbance, ensuring effective utilization of a wider range of the solar spectrum for photocatalysis. Therefore, SiNR/MXene/TiO2 ternary nanocomposites hold great promise for developing high-performance photocatalysts for water purification applications, offering improved stability, repeatability, and enhanced photocatalytic efficiency.