NOVELTY - Forming a film of nanocomposites of carbon nanotubes (CNTs) and platinum (Pt) nanoparticles comprises: (a) providing a first solution that contains CNTs; (b) providing a second solution that contains Pt nanoparticles; (c) combining the first solution and the second solution to form a third solution; and (d) filtering the third solution through a nanoporous membrane using vacuum filtration to obtain a film of nanocomposites of CNTs and Pt nanoparticles.    USE - The methods are used for forming a film of nanocomposites of CNTs and nanoparticles (claimed) via vacuum filtration.    DETAILED DESCRIPTION - INDEPENDENT CLAIMS are included for:    (1) a method comprising: (a) combining a first solution that contains CNTs and a second solution that contains titanium dioxide (TiO2) nanoparticles to form a third solution; and (b) filtering the third solution through a nanoporous membrane using vacuum filtration to obtain a film of nanocomposites of CNTs and TiO2 nanoparticles;    (2) a method comprising: (a) combining a first solution that contains silicon (Si) nanoparticles, a second solution that contains graphene sheets, and a third solution that contains CNTs, to form a fourth solution; and (b) filtering the fourth solution through a nanoporous membrane using vacuum filtration to obtain a film of nanocomposites of Si-graphene-CNT;    (3) a method comprising: (a) combining a first solution that contains CNTs and a second solution that contains non-carbon nanoparticles to form a third solution; and (b) filtering the third solution through a nanoporous membrane using vacuum filtration to obtain a film of nanocomposites of CNTs and non-carbon nanoparticles;    (4) an article of manufacture made by the methods above;    (5) a dye-sensitized solar cell comprising: (a) an anode; (b) a cathode comprising a film of nanocomposites of CNTs and Pt nanoparticles; and (c) an active layer disposed between the anode and the cathode and immersed in an electrolyte solution, the active layer comprising porous titanium dioxide covered with photosensitive dye; and    (6) a lithium-ion battery cell comprising: (a) an anode comprising a film of nanocomposites of Si-graphene-CNT; (b) a cathode; and (c) an electrolyte.