## 3 Results
### Catalyst Characterization
The XPS analysis reveals significant differences in the elemental % at composition across the three samples. For the TWM sample (Figure S1a), the primary element detected is carbon (73.6%), accompanied by substantial amounts of oxygen (14.3%) and nitrogen (12.1%). In contrast, the CuFeNPs sample (Figure S1b)  
Figure 1: XRD diffractogram obtained for: (**a**) TWM, (**b**) CuFeNPs, and (**c**) CuFeNP@TWM. predominantly consists of oxygen (49.8%), iron (34.2%), and copper (11.1%). The composite sample CuFeNPs@TWM (Figure S1c) displays a mixed elemental composition, inheriting characteristics from both TWM and CuFeNPs. This sample contains significant amounts of carbon (47.2%) and oxygen (31.9%), with measurable quantities of iron (10.8%) and copper (8.6%), alongside a minor presence of nitrogen (1.6%). These values indicate that the synthesis process successfully integrates CuFe nanoparticles with the TWM matrix, resulting in a composite material with diverse elemental characteristics, potentially enhancing its functional properties for various applications. In addition to the survey analysis, high-resolution spectra of the elements identified in CuFeNPs@TWM were examined (Figure 3), offering valuable insights into the chemical states and interactions within the material. The high-resolution C 1s spectrum (Figure 3a) revealed the presence of C=O, C-N, and C-C sites, which are characteristic of carbon-based materials derived from biomass. The C=O and C-N functionalities suggest the retention of oxygen- and nitrogen-containing groups after pyrolysis, which could enhance the material's hydrophilicity and possibly facilitate catalytic activity by providing reactive sites [62]. The C-C groups likely contribute to the overall stability and conductivity of the carbon matrix, supporting electron transfer processes essential in catalytic applications. The N 1s spectrum (Figure 3b) further confirmed the presence of nitrogen functionalities such as N-pyridinic, N-pyridnic, and N-oxide. These nitrogen sites are particularly significant because they can enhance electron-donating properties, improve binding affinity with metal nanoparticles, and increase active site density, all of which can enhance catalytic performance [63; 64]. N-pyridnic and N-pyridnic groups, for example, are often associated with improved electron conductivity, while N-oxide groups could provide acidic sites or influence metal-support interactions, thereby stabilizing the nanoparticles [65]. For the O 1s spectrum (Figure 3c), three distinct sites were identified: C-O, C=O, and O-M (where M denotes Fe and/or Cu). The C-O and C=O sites are typically related to residual oxygen functionalities from the biomass and could play a role in modulating surface polarity and adsorption characteristics. M-O could be attributed to the metallic oxides of the prepared nanoparticles [66]. The Fe 2p spectrum (Figure 3d) exhibited characteristic peaks at binding energies corresponding to Fe 2p\({}_{3/2}\) and 2p\({}_{1/2}\), indicating the presence of both Fe\({}^{2+}\) and Fe\({}^{3+}\) oxidation states. This mixed-valence state of iron could be advantageous for redox reactions, as Fe\({}^{2+}\)/Fe\({}^{3+}\) cycling is often central to catalytic processes like the Fenton reaction [67; 68]. The presence of both oxidation states also implies that the iron species are stabilized in a form conducive to electron exchange, which could enhance catalytic efficiency. Likewise, in the Cu 2p spectrum (Figure 3e), the detection of Cu\({}^{+}\) and Cu\({}^{2+}\) species highlights the coexistence of copper in different oxidation states, which could facilitate a wider range of redox reactions. The Cu\({}^{+}\) species, often associated with high electron density, may  
Figure 2: Raman spectra of (**a**) TWM, (**b**) CuFeNPs, and (**c**) CuFeNP@TWM. provide active sites for specific catalytic processes, while the presence of Cu\({}^{2+}\) could be beneficial for reactions requiring electron donation, such as the recuperation of the Fe\({}^{2+}\) catalyst [6; 69].