Bimetallic heterostructures are successful candidate for heterogeneous catalysis because of their enhanced or new chemical and physical properties. In heterogeneous catalysis, the noble-non noble nanocrystals are surprisingly useful because of reduced cost and noticeable catalytic efficiency. The cheap Cu nanocrystals can be an ideal substrate to form metal heterostructures with noble and non-metal nanocrystals, and the resulting nanostructures were reported as efficient catalyst towards nitrophenol reduction [170–177]. Catalytic efficiency of roughness controlled Cu nanowires and Cu-Ag heterostructures synthesized by controlling the reactant ratio of Cu2+- Cu+ in the copper precursor [36]. The improved catalytic reduction rate of the roughened Cu NWs compared with smooth NWs was found to be due to the increased surface area of the nanocatalyst along with the presence of Cu-Ag junction. Besides the synergistic effects of higher electron chemical potential of Cu relative to Ag, the higher electron conductivity of Ag results in slight alternation in the local electronic structure also significantly contributes to enhancing the catalytic activity relative to the monometal catalyst [36,178,179]. For the first time, magnetic bimetallic Ni/Cu nanowires were suggested as a robust and recyclable catalyst for the paranitrophenol reduction system by Sun et al. [180]. The rate constant value reported for the bimetallic Cu-Ni system was 0.0154 s−1, with a convert ratio of 98.7%, which decreases to only 92.25% even after ten consecutive cycles of the reduction reaction. The paramagnetic nature presented by the developed catalyst offers good reusability of the catalyst by simply removing the catalyst from the reaction solution using an external magnetic field and appears as low-cost promising applications in the field of wastewater treatment.

N-situ exsolution triggered hydrogenated F-Ni/Cu-P-RT from Ni/Cu-P-RT (a bimetallic phosphate) possessing excellent catalytic activity towards nitrophenol reduction [181]. In comparison to the monometallic counterparts, including Ni-P-RT and Cu-P-RT, the bimetallic Ni/Cu-P-RT exhibits a reaction rate of 2.85/4.23/6.6 min−1 at 20, 30, and 40 °C with the activation energy 32 kJ/mol. The observed induction period during the reaction was found to be due to the evolution of metal nanoparticles during the reaction process but was removed by the combination of Cu and Ni with phosphate (Fig. 9).

Yes, it's possible to calcine two different base metal nanocatalysts simultaneously in a tubular furnace, but there are important considerations. he key factors are compatibility in terms of thermal stability, decomposition temperatures, and the potential for cross-contamination. If both materials require similar calcination conditions (temperature, gas atmosphere, time), and are physically separated (e.g., in different crucibles or "boats"), you can proceed safely. However, if one releases volatile species or decomposes into reactive intermediates, it may alter the surface or composition of the other. For best results, ensure there's no chemical interaction during heating and monitor uniform gas flow within the furnace.