TECHNOLOGY FOCUS - INORGANIC CHEMISTRY - Preferred Method: The method (M1) further involves treating the carbon material with an acid or surfactant. The coupling step involves coating the carbon material with the x-ray absorbing material, where the coupling step occurs in situ. The method (M1) further involves coupling the carbon material with a metal oxide. Preferred Components: The carbon material is selected from carbon nanotubes, graphenes, carbon fibers and/or amorphous carbons. The carbon material comprises a vapor grown carbon fiber (VGCF). The carbon material comprises carbon nanotubes selected from single-walled carbon nanotubes, multi-walled carbon nanotubes and/or double-walled carbon nanotubes. The carbon material is treated with a surfactant or acid. The carbon material is further coupled with a metal oxide. The metal oxide is selected from SiO2, Na2O, K2O, Li2O and/or Rb2O. The x-ray absorbing material is a lead-based compound selected from PbS, PbO, PbO2, PbSO3, PbSO4, Pb(NO3)2, Ph3O4, Pb3(OH)2(CO3)2, Ph(OH)42-, Pb(OH)62-, PbCO3, PbCl+, PbCl2, PbCl3- and/or PbCl4-2. The x-ray absorbing material is a bismuth-based compound selected from Bi2S3, Bi2O3, Bi2O5, BiF5, BiF3, BiBr3, BiI3, BiH3, Bi2(SO4)3, Bi(NO3)3, BiO2-, BiO3-3 and/or BiCl3. The x-ray absorbing material is coated on the carbon material.    TECHNOLOGY FOCUS - ORGANIC CHEMISTRY - Preferred Components: The surfactant is sodium dodecyl sulfate (SDS). EXAMPLE - Preparation of x-ray absorbing composition was carried as follows: multi-walled carbon nanotubes (MWNTs) (30 mg) were probe sonicated in a sodium dodecyl sulfate (SDS) solution (150 ml) for 10 minutes, followed by centrifugation for 10 minutes at 4400 rpm. The supernatant was saved, and the process of centrifugation was repeated 3 times. The MWNT-SDS solution (3 ml) was mixed with ammonium hydroxide (0.6 ml), thiourea (0.6 ml), and lead acetate (0.6 ml). The mixture was stirred for 4 hours at room temperature. After the allotted reaction time, the mixture was added to EtOH (35 ml) and centrifuged for 10 minutes at 4400 rpm. The decant was discarded and centrifugation/discarding process was repeated 5 more times using ethanol to obtain x-ray absorbing composition.